3.

5 GSPS Direct Digital Synthesizer

with 12-Bit DAC
Data Sheet AD9914
FEATURES FUNCTIONAL BLOCK DIAGRAM
3.5 GSPS internal clock speed
AD9914 HIGH SPEED PARALLEL
Integrated 12-bit DAC MODULATION
PORT
Frequency tuning resolution to 190 pHz
16-bit phase tuning resolution
12-bit amplitude scaling
Programmable modulus
Automatic linear and nonlinear frequency sweeping LINEAR
SWEEP 3.5GSPS DDS CORE 12-BIT DAC
capability BLOCK

32-bit parallel datapath interface

8 frequency/phase offset profiles
Phase noise: −128 dBc/Hz (1 kHz offset at 1396 MHz)
Wideband SFDR < −50 dBc
Serial or parallel input/output control REF CLK
MULTIPLIER TIMING AND CONTROL
1.8 V/3.3 V power supplies
Software and hardware controlled power-down
88-lead LFCSP package
PLL REF CLK multiplier
SERIAL OR PARALLEL
Phase modulation capability DATA PORT

10836-001
Amplitude modulation capability

APPLICATIONS Figure 1.

Agile LO frequency synthesis

Programmable clock generator
FM chirp source for radar and scanning systems
Test and measurement equipment
Acousto-optic device drivers
Polar modulator
Fast frequency hopping

Rev. F Document Feedback

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Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com
AD9914 Data Sheet

TABLE OF CONTENTS
Features .............................................................................................. 1 12-Bit DAC Output .................................................................... 20
Applications ....................................................................................... 1 DAC Calibration Output ........................................................... 20
Functional Block Diagram .............................................................. 1 Reconstruction Filter ................................................................. 20
Revision History ............................................................................... 2 Clock Input (REF_CLK/REF_CLK) ........................................ 21
General Description ......................................................................... 3 PLL Lock Indication .................................................................. 22
Specifications..................................................................................... 4 Output Shift Keying (OSK) ....................................................... 22
DC Specifications ......................................................................... 4 Digital Ramp Generator (DRG) ............................................... 23
AC Specifications.......................................................................... 5 Power-Down Control ................................................................ 27
Absolute Maximum Ratings ............................................................ 8 Programming and Function Pins ................................................. 28
Thermal Performance .................................................................. 8 Serial Programming ....................................................................... 31
ESD Caution .................................................................................. 8 Control Interface—Serial Input/Output ................................. 31
Pin Configuration and Function Descriptions ............................. 9 General Serial Input/Output Operation.................................. 31
Typical Performance Characteristics ........................................... 12 Instruction Byte .......................................................................... 31
Equivalent Circuits ......................................................................... 16 Serial Input/Output Port Pin Descriptions ............................. 31
Theory of Operation ...................................................................... 17 Serial Input/Output Timing Diagrams .................................... 32
Single Tone Mode ....................................................................... 17 MSB/LSB Transfers .................................................................... 32
Profile Modulation Mode .......................................................... 17 Parallel Programming (8-/16-Bit) ................................................ 33
Digital Ramp Modulation Mode .............................................. 17 Register Map and Bit Descriptions .............................................. 34
Parallel Data Port Modulation Mode....................................... 17 Register Bit Descriptions ........................................................... 39
Programmable Modulus Mode ................................................. 17 Outline Dimensions ....................................................................... 45
Mode Priority .............................................................................. 18 Ordering Guide .......................................................................... 45
Functional Block Detail ................................................................. 19
DDS Core..................................................................................... 19

REVISION HISTORY
6/2016—Rev. E to Rev. F 7/2013—Rev. A to Rev. B
Changes to Figure 19 ...................................................................... 14 Change to CMOS Logic Outputs Parameter, Table 1 ...................4
Changes to Table 2.............................................................................7
1/2016—Rev. D to Rev. E Changes to DDS Core Section ...................................................... 19
Changes to DDS Core Section ...................................................... 19 Changes to Phase-Locked Loop (PLL) Multiplier Section ....... 21
Change to Figure 30 ....................................................................... 19 Changed PLL Charge Pump Section to PLL Charge Pump/
Updated Outline Dimensions ....................................................... 45 Total Feedback Divider Section; Changes to Table 8, PLL
Loop Filter Components Section, and Figure 34 ....................... 22
1/2014—Rev. C to Rev. D Change to Table 14 ......................................................................... 34
Changes to Digital Timing Specifications Parameter, Table 2.... 5 Changes to Bits [15:8], Table 17 ................................................... 42
Changes to Figure 23 ...................................................................... 15
Change to DAC Calibration Output Section .............................. 20 8/2012—Rev. 0 to Rev. A
Change to Address 0x02, Table 14................................................ 34 Changes to Features Section ............................................................1
Changes to Table 17 ........................................................................ 41 Changed Differential Input Voltage Unit from mV p-p to V p-p .....4
Changes to Table 14 ....................................................................... 34
11/2013—Rev. B to Rev. C Changes to Table 16 ....................................................................... 40
Changes to Table 2 ............................................................................ 5 Changes to Table 28 ....................................................................... 44
Change to Programming and Function Pins Section ................ 30 Updated Outline Dimensions ....................................................... 45

7/2012—Revision 0: Initial Version

Rev. F | Page 2 of 45
Data Sheet AD9914

GENERAL DESCRIPTION
The AD9914 is a direct digital synthesizer (DDS) featuring a parallel input/output port. The AD9914 also supports a user
12-bit DAC. The AD9914 uses advanced DDS technology, coupled defined linear sweep mode of operation for generating linear
with an internal high speed, high performance DAC to form a swept waveforms of frequency, phase, or amplitude. A high
digitally programmable, complete high frequency synthesizer speed, 32-bit parallel data input port is included, enabling high
capable of generating a frequency-agile analog output sinusoidal data rates for polar modulation schemes and fast reprogramming
waveform at up to 1.4 GHz. The AD9914 enables fast frequency of the phase, frequency, and amplitude tuning words.
hopping and fine tuning resolution (64-bit capable using The AD9914 is specified to operate over the extended industrial
programmable modulus mode). The AD9914 also offers fast temperature range (see the Absolute Maximum Ratings section).
phase and amplitude hopping capability. The frequency tuning
and control words are loaded into the AD9914 via a serial or

AD9914

OUTPUT
OSK SHIFT DDS
KEYING DAC_RSET
AMPLITUDE (A)
2 A Acos (Ȧt + ș)
DRCTL DIGITAL PHASE (ș) DAC AOUT
DRHOLD RAMP DATA ș 12-BIT
GENERATOR ROUTE FREQUENCY (Ȧ) AOUT
DROVER AND Ȧ Asin (Ȧt + ș)
PARTITION
CONTROL
3 CLOCK
INTERNAL
PS[2:0] PROGRAMMING
REGISTERS SYSCLK
I/O_UPDATE
REF_CLK

32 INTERNAL CLOCK TIMING REF_CLK

AND CONTROL PLL
D0 TO D31

4
F0 TO F3 POWER- MULTICHIP
DOWN SYNCHRONIZATION
CONTROL
SYNC_CLK
LOOP_FILTER
EXT_PWR_DWN

SYNC_IN
SYNC_OUT

MASTER_RESET

10836-002
Figure 2. Detailed Block Diagram

Rev. F | Page 3 of 45
AD9914 Data Sheet

SPECIFICATIONS
DC SPECIFICATIONS
AVDD (1.8 V) and DVDD (1.8 V) = 1.8 V ± 5%, AVDD (3.3 V) and DVDD_I/O (3.3 V) = 3.3 V ± 5%, TA = 25°C, RSET = 3.3 kΩ,
IOUT = 20 mA, external reference clock frequency = 3.5 GHz with reference clock (REF CLK) multiplier bypassed, unless otherwise noted.

Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
SUPPLY VOLTAGE
DVDD_I/O 3.135 3.30 3.465 V Pin 16, Pin 83
DVDD 1.71 1.80 1.89 V Pin 6, Pin 23, Pin 73
AVDD (3.3 V) 3.135 3.30 3.465 V Pin 34, Pin 36, Pin 39, Pin 40, Pin 43, Pin 47, Pin 50, Pin 52,
Pin 53, Pin 60
AVDD (1.8 V) 1.71 1.80 1.89 V Pin 32, Pin 56, Pin 57
SUPPLY CURRENT See also the total power dissipation specifications
IDVDD_I/O 20 mA Pin 16, Pin 83
IDVDD 433 mA Pin 6, Pin 23, Pin 73
IAVDD(3.3V) 640 mA Pin 34, Pin 36, Pin 39, Pin 40, Pin 43, Pin 47, Pin 50, Pin 52,
Pin 53, Pin 60
IAVDD(1.8V) 178 mA Pin 32, Pin 56, Pin 57
TOTAL POWER DISSIPATION
Base DDS Power, PLL Disabled 2392 3091 mW 3.5 GHz, single-tone mode, modules disabled, linear
sweep disabled, amplitude scaler disabled
Base DDS Power, PLL Enabled 2237 2627 mW 2.5 GHz, single-tone mode, modules disabled, linear
sweep disabled, amplitude scaler disabled
Linear Sweep Additional Power 28 mW
Modulus Additional Power 20 mW
Amplitude Scaler Additional Power 138 mW Manual or automatic
Full Power-Down Mode 400 616 mW Using either the power-down and enable register or the
EXT_PWR_DWN pin
CMOS LOGIC INPUTS
Input High Voltage (VIH) 2.0 DVDD_I/O V
Input Low Voltage (VIL) 0.8 V
Input Current (IINH, IINL) ±60 ±200 µA At VIN = 0 V and VIN = DVDD_I/O
Maximum Input Capacitance (CIN) 3 pF
CMOS LOGIC OUTPUTS
Output High Voltage (VOH) 2.7 DVDD_I/O V IOH = 1 mA
Output Low Voltage (VOL) 0.4 V IOL = 1 mA
REF CLK INPUT CHARACTERISTICS REF CLK inputs must always be ac-coupled (both
single-ended and differential)
REF CLK Multiplier Bypassed
Input Capacitance 1 pF Single-ended, each pin
Input Resistance 1.4 kΩ Differential
Internally Generated DC Bias 2 V
Voltage
Differential Input Voltage 0.8 1.5 V p-p
REF CLK Multiplier Enabled
Input Capacitance 1 pF Single-ended, each pin
Input Resistance 1.4 kΩ Differential
Internally Generated DC Bias 2 V
Voltage
Differential Input Voltage 0.8 1.5 V p-p

Rev. F | Page 4 of 45
Data Sheet AD9914
AC SPECIFICATIONS
AVDD (1.8V) and DVDD (1.8V) = 1.8 V ± 5%, AVDD3 (3.3V) and DVDD_I/O (3.3V) = 3.3 V ± 5%, TA = 25°C, RSET = 3.3 kΩ, IOUT =
20 mA, external reference clock frequency = 3.5 GHz with reference clock (REF CLK) multiplier bypassed, unless otherwise noted.

Table 2.
Parameter Min Typ Max Unit Test Conditions/Comments
REF CLK INPUT Input frequency range
REF CLK Multiplier Bypassed
Input Frequency Range 500 3500 MHz Maximum fOUT is 0.4 × fSYSCLK
Duty Cycle 45 55 %
Minimum Differential Input Level 632 mV p-p Equivalent to 316 mV swing on each leg
System Clock (SYSCLK) PLL Enabled
VCO Frequency Range 2400 2500 MHz
VCO Gain (KV) 60 MHz/V
Maximum PFD Rate 125 MHz
CLOCK DRIVERS
SYNC_CLK Output Driver
Frequency Range 146 MHz
Duty Cycle 45 50 55 %
Rise Time/Fall Time (20% to 80%) 650 ps
SYNC_OUT Output Driver 10 pF load
Frequency Range 9.1 MHz
Duty Cycle 33 66 % CFR2 register, Bit 9 = 1
Rise Time (20% to 80%) 1350 ps 10 pF load
Fall Time (20% to 80%) 1670 ps 10 pF load
DAC OUTPUT CHARACTERISTICS
Output Frequency Range (1st 0 1750 MHz
Nyquist Zone)
Output Resistance 50 Ω Single-ended (each pin internally terminated
to AVDD (3.3 V))
Output Capacitance 1 pF
Full-Scale Output Current 20.48 mA Range depends on DAC RSET resistor
Gain Error −10 +10 % FS
Output Offset 0.6 μA
Voltage Compliance Range AVDD − AVDD + V
0.50 0.50
Wideband SFDR See the Typical Performance Characteristics
section
101.1 MHz Output −66 dBc 0 MHz to 1750 MHz
427.5 MHz Output −65 dBc 0 MHz to 1750 MHz
696.5 MHz Output −57 dBc 0 MHz to 1750 MHz
1396.5 MHz Output −52 dBc 0 MHz to 1750 MHz
Narrow-Band SFDR See the Typical Performance Characteristics
section
100.5 MHz Output −95 dBc ±500 kHz
427.5 MHz Output −95 dBc ±500 kHz
696.5 MHz Output −95 dBc ±500 kHz
1396.5 MHz Output −92 dBc ±500 kHz

Rev. F | Page 5 of 45
AD9914 Data Sheet
Parameter Min Typ Max Unit Test Conditions/Comments
DIGITAL TIMING SPECIFICATIONS
Time Required to Enter Power-Down 45 ns Power-down mode loses DAC/PLL calibration
settings
Time Required to Leave Power-Down 250 ns Must recalibrate DAC/PLL
Minimum Master Reset time 24 SYSCLK cycles
Maximum DAC Calibration Time (tCAL) 135 µs See the DAC Calibration Output section for
formula
Maximum PLL Calibration Time (tREF_CLK) 16 ms PFD rate = 25 MHz
8 ms PFD rate = 50 MHz
Maximum Profile Toggle Rate 2 SYNC_CLK
period
PARALLEL PORT TIMING
Write Timing
Address Setup Time to WR Active 1 ns
Address Hold Time to WR Inactive 0 ns
Data Setup Time to WR Inactive 3.8 ns
Data Hold Time to WR Inactive 0 ns
WR Minimum Low Time 2.1 ns
WR Minimum High Time 3.8 ns
Minimum WR Time 10.5 ns
Read Timing
Address to Data Valid 92 ns
Address Hold to RD Inactive 0 ns
RD Active to Data Valid 69 ns
RD Inactive to Data Tristate 50 ns
RD Minimum Low Time 69 ns
RD Minimum High Time 50 ns
SERIAL PORT TIMING
SCLK Clock Rate (1/tCLK ) 80 MHz SCLK duty cycle = 50%
SCLK Pulse Width High, tHIGH 1.5 ns
SCLK Pulse Width Low, tLOW 5.1 ns
SDIO to SCLK Setup Time, tDS 4.9 ns
SDIO to SCLK Hold Time, tDH 0 ns
SCLK Falling Edge to Valid Data on 78 ns
SDIO/SDO, tDV
CS to SCLK Setup Time, tS 4 ns
CS to SCLK Hold Time, tH 0 ns
CS Minimum Pulse Width High, tPWH 4 ns
DATA PORT TIMING
D[31:0] Setup Time to SYNC_CLK 2 ns
D[31:0] Hold Time to SYNC_CLK 0 ns
F[3:0] Setup Time to SYNC_CLK 2 ns
F[3:0] Hold Time to SYNC_CLK 0 ns
IO_UPDATE Pin Setup Time to 2 ns
SYNC_CLK
IO_UPDATE Pin Hold Time to 0 ns
SYNC_CLK
Profile Pin Setup Time to SYNC_CLK 2 ns
Profile Pin Hold Time to SYNC_CLK 0 ns
DR_CTL/DR_HOLD Setup Time to 2 ns
SYNC_CLK
DR_CTL/DR_HOLD Hold Time to 0 ns
SYNC_CLK

Rev. F | Page 6 of 45
Data Sheet AD9914
Parameter Min Typ Max Unit Test Conditions/Comments
DATA LATENCY (PIPELINE DELAY) SYSCLK cycles = fS = system clock frequency
in GHz
Single Tone Mode or Profile Mode
(Matched Latency Disabled)
Frequency 318 SYSCLK cycles OSK disabled
342 SYSCLK cycles OSK enabled
Phase 294 SYSCLK cycles OSK disabled
318 SYSCLK cycles OSK enabled
Amplitude 102 SYSCLK cycles OSK enabled
Single Tone Mode or Profile Mode
(Matched Latency Enabled)
Frequency 318 SYSCLK cycles OSK disabled
342 SYSCLK cycles OSK enabled
Phase 318 SYSCLK cycles OSK disabled
342 SYSCLK cycles OSK enabled
Amplitude 342 SYSCLK cycles OSK enabled
Modulation Mode with 32-Bit
Parallel Port (Matched Latency
Disabled)
Frequency 318 SYSCLK cycles OSK disabled
342 SYSCLK cycles OSK enabled
Phase 294 SYSCLK cycles OSK disabled
318 SYSCLK cycles OSK enabled
Amplitude 102 SYSCLK cycles OSK enabled

Modulation Mode with 32-Bit Parallel

Port (Matched Latency Enabled)
Frequency 318 SYSCLK cycles OSK disabled
342 SYSCLK cycles OSK enabled
Phase 318 SYSCLK cycles OSK disabled
342 SYSCLK cycles OSK enabled
Amplitude 342 SYSCLK cycles OSK enabled
Sweep Mode (Match Latency
Disabled)
Frequency 342 SYSCLK cycles OSK disabled
366 SYSCLK cycles OSK enabled
Phase 318 SYSCLK cycles OSK disabled
342 SYSCLK cycles OSK enabled
Amplitude 126 SYSCLK cycles OSK enabled
Sweep Mode (Match Latency
Enabled)
Frequency 342 SYSCLK cycles OSK disabled
366 SYSCLK cycles OSK enabled
Phase 342 SYSCLK cycles OSK disabled
366 SYSCLK cycles OSK enabled
Amplitude 366 SYSCLK cycles OSK enabled

Rev. F | Page 7 of 45
AD9914 Data Sheet

ABSOLUTE MAXIMUM RATINGS

Table 3. THERMAL PERFORMANCE
Parameter Rating Table 4.
AVDD (1.8 V), DVDD (1.8 V) Supplies 2V Symbol Description Value1 Unit
TJA
AVDD (3.3 V), DVDD_I/O (3.3 V) Supplies 4V Junction-to-ambient thermal 24.1 °C/W
Digital Input Voltage −0.7 V to +4 V resistance (still air) per JEDEC
Digital Output Current 5 mA JESD51-2
Storage Temperature Range −65°C to +150°C TJMA Junction-to-ambient thermal 21.3 °C/W
Operating Temperature Range −40°C to +85°C resistance (1.0 m/sec airflow)
per JEDEC JESD51-6
TJMA
Maximum Junction Temperature 150°C
Lead Temperature (10 sec Soldering) 300°C Junction-to-ambient thermal 20.0 °C/W
resistance (2.0 m/sec air flow)
Stresses at or above those listed under Absolute Maximum per JEDEC JESD51-6
Ratings may cause permanent damage to the product. This is a TJB Junction-to-board thermal 13.3 °C/W
stress rating only; functional operation of the product at these resistance (still air) per JEDEC
JESD51-8
<JB
or any other conditions above those indicated in the operational
Junction-to-board characterization 12.8 °C/W
section of this specification is not implied. Operation beyond
parameter (still air) per JEDEC
the maximum operating conditions for extended periods may JESD51-6
affect product reliability. TJC Junction-to-case thermal resistance 2.21 °C/W
<JT Junction-to-top-of-package 0.23 °C/W
characterization parameter (still air)
per JEDEC JESD51-2
1
Results are from simulations. PCB is JEDEC multilayer. Thermal performance
for actual applications requires careful inspection of the conditions in the
application to determine if they are similar to those assumed in these
calculations.

ESD CAUTION

Rev. F | Page 8 of 45
Data Sheet AD9914

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

MASTER_RESET

EXT_PWR_DWN
DVDD_I/O (3.3V)
I/O_UPDATE

DVDD (1.8V)
SYNC_CLK
DGND

DGND
D18
D19

D20
D21
D22
D23
D24
D25
D26

D27
D28
D29
D30
D31
88
87

82
86
85
84
83

81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
D17 1 66 OSK
D16 2 65 DROVER
D15/A7 3 64 DRHOLD
D14/A6 4 63 DRCTL
D13/A5 5 62 SYNC_IN
DVDD (1.8V) 6 61 SYNC_OUT
DGND 7 60 AVDD (3.3V)
D12/A4 8 59 REF
D11/A3 9 58 LOOP_FILTER
D10/A2 10 AD9914 57 AVDD (1.8V)
D9/A1 11 TOP VIEW 56 AVDD (1.8V)
D8/A0 12 (Not to Scale) 55 REF CLK
D7 13 54 REF CLK
D6 14 53 AVDD (3.3V)
D5 15 52 AVDD (3.3V)
DVDD_I/O (3.3V) 16 51 AGND
DGND 17 50 AVDD (3.3V)
D4/SYNCIO 18 49 AGND
D3/SDO 19 48 DAC_RSET
D2/SDIO/WR 20 47 AVDD (3.3V)
D1/SCLK/RD 21 46 AGND
D0/CS/PWD 22 45 DAC_BP
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
F0
F1
F2
F3
PS0
PS1
PS2
DGND

AGND

AGND

AGND
AGND

AGND
AOUT
AOUT
AVDD (1.8V)

AVDD (3.3V)

AVDD (3.3V)
AVDD (3.3V)

AVDD (3.3V)
AVDD (3.3V)
DVDD (1.8V)

10836-003
NOTES
1. THE EPAD MUST BE SOLDERED TO GROUND.

Figure 3. Pin Configuration

Table 5. Pin Function Descriptions

Pin No. Mnemonic I/O1 Description
1, 2, 13 to 15, 68 D5 to D7, D16 to I/O Parallel Port Pins. The 32-bit parallel port offers the option for serial or parallel programming
to 72, 75 to 81, D31, D27 to D31 of the internal registers. In addition, the parallel port can be configured to provide direct FSK,
87, 88 PSK, or ASK (or combinations thereof ) modulation data. The 32-bit parallel port configuration
is set by the state of the four function pins (F0 to F3).
3 D15/A7 I/O Parallel Port Pin/Address Line. The state of the F0 to F3 function pins determines if this pin
acts as a line for direct FSK, PSK, or ASK data or as an address line for programming the
internal registers.
4 D14/A6 I/O Parallel Port Pin/Address Line. The state of the F0 to F3 function pins determines if this pin
acts as a line for direct FSK, PSK, or ASK data or as an address line for programming the
internal registers.
5 D13/A5 I/O Parallel Port Pin/Address Line. The state of the F0 to F3 function pins determines if this pin
acts as a line for direct FSK, PSK, or ASK data or as an address line for programming the
internal registers.
8 D12/A4 I/O Parallel Port Pin/Address Line. The state of the F0 to F3 function pins determines if this pin
acts as a line for direct FSK, PSK, or ASK data or as an address line for programming the
internal registers.
9 D11/A3 I/O Parallel Port Pin/Address Line. The state of the F0 to F3 function pins determines if this pin
acts as a line for direct FSK, PSK, or ASK data or as an address line for programming the
internal registers.
10 D10/A2 I/O Parallel Port Pin/Address Line. Multipurpose pin depending on the state of the function pins
(F0 to F3). The state of the F0 to F3 function pins determines if this pin acts as a line for direct
FSK, PSK, or ASK data or as an address line for programming the internal registers.
11 D9/A1 I/O Parallel Port Pin/Address Line. Multipurpose pin depending on the state of the function pins
(F0 to F3). The state of the F0 to F3 function pins determines if this pin acts as a line for direct
FSK, PSK, or ASK data or as an address line for programming the internal registers.

Rev. F | Page 9 of 45
AD9914 Data Sheet
Pin No. Mnemonic I/O1 Description
12 D8/A0 I/O Parallel Port Pin/Address Line. The state of the F0 to F3 function pins determines if this pin
acts as a line for direct FSK, PSK, or ASK data or as an address line for programming the
internal registers.
18 D4/SYNCIO I Parallel Port Pin/Serial Port Synchronization Pin. This pin is D4 for direct FSK, PSK, or ASK data.
If serial mode is invoked via F0 to F3, this pin resets the serial port.
19 D3/SDO I/O Parallel Port Pin/Serial Data Output. This pin is D3 for direct FSK, PSK, or ASK data. If serial
mode is invoked via F0 to F3, this pin is used for readback mode for serial operation.
20 D2/SDIO/WR I/O Parallel Port Pin/Serial Data Input and Output/Write Input. This pin is D2 for direct FSK, PSK, or
ASK data. If serial mode is invoked via F0 to F3, this pin is used for the SDIO for serial operation. If
parallel mode is enabled, this pin is writes to change the values of the internal registers.
21 D1/SCLK/RD I Parallel Port Pin/Serial Clock/Read Input. This pin is D1 for direct FSK, PSK, or ASK data. If serial
mode is invoked via F0 to F3, this pin is used for SCLK for serial operation. If parallel mode is
enabled, this pin reads back the value of the internal registers.
22 D0/CS/PWD I Parallel Port Pin/Chip Select/Parallel Width. This pin is D0 for direct FSK, PSK, or ASK data. If
serial mode is invoked via F0 to F3, this pin is used for the chip select for serial operation. If
parallel mode is enabled, this pin sets either 8-bit data or16-bit data.
6, 23, 73 DVDD (1.8V) I Digital Core Supplies (1.8 V).
7, 17, 24, 74, 84 DGND I Digital Ground.
16, 83 DVDD_I/O (3.3V) I Digital Input/Output Supplies (3.3 V).
32, 56, 57 AVDD (1.8V) I Analog Core Supplies (1.8 V).
33, 35, 37, 38, AGND I Analog Ground.
44, 46, 49, 51
34, 36, 39, 40, AVDD (3.3V) I Analog DAC Supplies (3.3 V).
43, 47, 50, 52,
53, 60
25, 26, 27 PS0 to PS2 I Profile Select Pins. Digital inputs (active high). Use these pins to select one of eight
phase/frequency profiles for the DDS. Changing the state of one of these pins transfers the
current contents of all input/output buffers to the corresponding registers. State changes
must be set up on the SYNC_CLK pin (Pin 82).
28, 29, 30, 31 F0 to F3 I Function Pins. Digital inputs. The state of these pins determines if a serial or parallel interface
is used. In addition, the function pins determine how the 32-bit parallel data-word is
partitioned for FSK, PSK, or ASK modulation mode.
41 AOUT O DAC Complementary Output Source. Analog output (voltage mode). Internally connected
through a 50 Ω resistor to AVDD (3.3 V).
42 AOUT O DAC Output Source. Analog output (voltage mode). Internally connected through a 50 Ω
resistor to AVDD (3.3 V).
45 DAC_BP I DAC Bypass Pin. Provides access to the common control node of the DAC current sources.
Connecting a capacitor between this pin and ground can improve noise performance at the
DAC output.
48 DAC_RSET O Analog Reference. This pin programs the DAC output full-scale reference current. Connect a
3.3 kΩ resistor to AGND.
54 REF_CLK I Complementary Reference Clock Input. Analog input.
55 REF_CLK I Reference Clock Input. Analog input.
58 LOOP_FILTER O External PLL Loop Filter Node.
59 REF O Local PLL Reference Supply. Typically at 2.05 V.
61 SYNC_OUT O Digital Synchronization Output. This pin synchronizes multiple chips.
62 SYNC_IN I Digital Synchronization Input. This pin synchronizes multiple chips.
63 DRCTL I Ramp Control. Digital input (active high). This pin controls the sweep direction (up/down).
64 DRHOLD I Ramp Hold. Digital input (active high). Pauses the sweep when active.
65 DROVER O Ramp Over. Digital output (active high). This pin switches to Logic 1 when the digital ramp
generator reaches the programmed upper or lower limit.
66 OSK I Output Shift Keying. Digital input (active high). When the OSK features are placed in either
manual or automatic mode, this pin controls the OSK function. In manual mode, it toggles
the multiplier between 0 (low) and the programmed amplitude scale factor (high). In
automatic mode, a low sweeps the amplitude down to zero and a high sweeps the amplitude
up to the amplitude scale factor.

Rev. F | Page 10 of 45
Data Sheet AD9914
Pin No. Mnemonic I/O1 Description
67 EXT_PWR_DWN I External Power-Down. Digital input (active high). A high level on this pin initiates the
currently programmed power-down mode.
82 SYNC_CLK O Clock Output. Digital output. Many of the digital inputs on the chip, such as I/O_UPDATE,
PS[2:0], and the parallel data port (D0 to D31), must be set up on the rising edge of
this signal.
85 MASTER_RESET I Master Reset. Digital input (active high). Clears all memory elements and sets registers to
default values.
86 I/O_UPDATE I Input/Output Update. Digital input (active high). A high on this pin transfers the contents of
the input/output buffers to the corresponding internal registers.
EPAD Exposed Pad. The EPAD must be soldered to ground.
1
I = input, O = output.

Rev. F | Page 11 of 45
AD9914 Data Sheet

TYPICAL PERFORMANCE CHARACTERISTICS

Nominal supply voltage; DAC RSET = 3.3 kΩ, TA = 25°C, unless otherwise noted.

0 0

–10 –10

–20 –20

–30 –30

–40 –40
SFDR (dBc)

SFDR (dBc)
–50 –50

–60 –60

–70 –70

–80 –80

–90 10836-004
–90

10836-007
–100 –100
START 0Hz 175MHz/DIV STOP 1.75GHz CENTER 171.5MHz 50kHz/DIV SPAN 500kHz

Figure 4. Wideband SFDR at 171.5 MHz Figure 7. Narrow-Band SFDR at 171.5 MHz,
SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed) SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed)

0 0

–10 –10

–20 –20

–30 –30

–40 –40
SFDR (dBc)
SFDR (dBc)

–50 –50

–60 –60

–70 –70

–80 –80

–90 –90
10836-005

10836-008
–100 –100
START 0Hz 175MHz/DIV STOP 1.75GHz CENTER 427.5MHz 50kHz/DIV SPAN 500kHz

Figure 5. Wideband SFDR at 427.5 MHz Figure 8. Narrow-Band SFDR at 427.5 MHz,
SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed) SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed)

0 0

–10 –10

–20 –20

–30 –30

–40
SFDR (dBc)

–40
SFDR (dBc)

–50 –50

–60 –60

–70 –70

–80 –80

–90 –90
10836-009
10836-006

–100 –100
START 0Hz 175MHz/DIV STOP 1.75GHz CENTER 696.5MHz 50kHz/DIV SPAN 500kHz

Figure 6. Wideband SFDR at 696.5 MHz, Figure 9. Narrow-Band SFDR at 696.5 MHz,
SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed) SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed)

Rev. F | Page 12 of 45
Data Sheet AD9914
0 0

–10 –10

–20 –20

–30 –30

–40 –40

SFDR (dBc)
SFDR (dBc)

–50 –50

–60 –60

–70 –70

–80 –80

–90 –90

10836-013
10836-010
–100 –100
START 0Hz 175MHz/DIV STOP 1.75GHz CENTER 1396.5MHz 50kHz/DIV SPAN 500kHz

Figure 10. Wideband SFDR at 1396.5 MHz, Figure 13. Narrow-Band SFDR at 1396.5 MHz,
SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed) SYSCLK = 3.5 GHz (SYSCLK PLL Bypassed)

0 –70

–80
–10
–90
–20

PHASE NOISE (dBc/Hz)

–100

–30 –110
SFDR (dBc)

–40 –120

–130
–50
–140 SMA AND
–60 ADCLK925
–150

–70 –160 SMA

–170

10836-014
–80
10 100 1k 10k 100k 1M 10M 100M
10836-011

0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40

fC/fS FREQUENCY OFFSET (Hz)

Figure 11. Wideband SFDR vs. Normalized fOUT Figure 14. Absolute Phase Noise of REF CLK Source Driving AD9914
SYSCLK = 3.5 GHz Rohde & Schwarz SMA100 Signal Generator at 3.5 GHz Buffered by Series
ADCLK925

0 –70
SYSCLK = 1.5GHz SYSCLK = 2.7GHz
SYSCLK = 1.6GHz SYSCLK = 2.8GHz –80
–10 SYSCLK = 1.7GHz SYSCLK = 2.9GHz
SYSCLK = 1.8GHz SYSCLK = 3.0GHz –90
–20 SYSCLK = 1.9GHz SYSCLK = 3.1GHz
PHASE NOISE (dBc/Hz)

SYSCLK = 2.0GHz –100

SYSCLK = 3.2GHz
–30 SYSCLK = 2.1GHz SYSCLK = 3.3GHz –110
SFDR (dBc)

SYSCLK = 2.2GHz SYSCLK = 3.4GHz

1396MHz
–40 SYSCLK = 2.3GHz SYSCLK = 3.5GHz –120
SYSCLK = 2.4GHz 696MHz
SYSCLK = 2.5GHz –130
–50
SYSCLK = 2.6GHz
–140
–60
–150
427MHz
–70 –160 171MHz

–80 –170
10836-015
10836-012

0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 10 100 1k 10k 100k 1M 10M 100M
fC/fS FREQUENCY OFFSET (Hz)

Figure 12. Wideband SFDR vs. Normalized fOUT, Figure 15. Absolute Phase Noise Curves of DDS Output at 3.5 GHz Operation
SYSCLK = 2.5 GHz to 3.5 GHz

Rev. F | Page 13 of 45
AD9914 Data Sheet
–70 –80

–80 –90
–90
–100
978MHz
PHASE NOISE (dBc/Hz)

PHASE NOISE (dBc/Hz)

–100 497MHz
–110
–110
1396MHz –120
–120
–130
–130
305MHz
–140
–140
NORMALIZED 122MHz
–150 REF CLK SOURCE –150

–160 –160

–170 –170

10836-016

10836-019
10 100 1k 10k 100k 1M 10M 100M 10 100 1k 10k 100k 1M 10M 100M
FREQUENCY OFFSET (Hz) FREQUENCY OFFSET (Hz)
Figure 16. Absolute Phase Noise Curves of Normalized REF CLK Source to Figure 19. Absolute Phase Noise Curves of DDS Output Using Internal PLL at
DDS Output at 1396 MHz (SYSCLK = 3.5 GHz) 2.5 GHz Operation
–60 –60
–70
–70
–80
–80
–90
PHASE NOISE (dBc/Hz)

PHASE NOISE (dBc/Hz) –90

–100
–110 –100

–120 1396MHz –110

1396MHz ABSOLUTE
–130
696MHz –120
–140
–130
–150
–140
–160 427MHz
1396MHz RESIDUAL
–170 –150
171MHz
–180 –160
10836-017

10836-020
10 100 1k 10k 100k 1M 10M 100M 10 100 1k 10k 100k 1M 10M 100M
FREQUENCY OFFSET (Hz) FREQUENCY OFFSET (Hz)
Figure 17. Residual Phase Noise Curves Figure 20. Residual PN vs. Absolute PN Measurement Curves at 1396 MHz

0.5 –60
3.3V ANALOG
–70

–80
0.4
–90
PHASE NOISE (dBc/Hz)
SUPPLY CURRENT (A)

–100
0.3 –110
1396MHz ABSOLUTE
1.8V DIGITAL –120

0.2 –130

1.8V ANALOG –140

–150 1396MHz RESIDUAL

0.1
–160

–170
3.3V DIGITAL
0 –180
10836-018

10836-021

500 1000 1500 2000 2500 3000 3500 4000 10 100 1k 10k 100k 1M 10M 100M
SYSTEM CLOCK (MHz) FREQUENCY OFFSET (Hz)
Figure 18. Power Supply Current vs. SYSCLK Figure 21. Residual Phase Noise vs. Normalized Absolute REF CLK Source
Phase Noise at 1396 MHz

Rev. F | Page 14 of 45
Data Sheet AD9914
930

920

FREQUENCY (MHz)
910

900

890
1

880

10836-022
870

10836-024
CH2 1.0V Ÿ M20.00ms IT 40.0ps/pt –6 –4 –2 0 2 4 6
A CH2 1.64V
TIME (ms)

Figure 22. SYNC_OUT (fSYSCLK/384) Figure 24. Measured Rising Linear Frequency Sweep

1.0 930

0.9
920
0.8

0.7

FREQUENCY (MHz)
910
0.6
TIME (ms)

0.5 900

0.4
890
0.3

0.2
880
0.1

0 870

10836-025
10836-023

500 1000 1500 2000 2500 3000 3500 –6 –4 –2 0 2 4 6

SYSTEM CLOCK RATE (MHz) TIME (ms)

Figure 23. DAC Calibration Time vs. SYSCLK Rate. See the DAC Calibration Figure 25. Measured Falling Linear Frequency Sweep
Output Section for Formula.

Rev. F | Page 15 of 45
AD9914 Data Sheet

EQUIVALENT CIRCUITS
AGND

IFS

CURRENT CURRENT
SWITCH SWITCH
SWITCH
ARRAY CONTROL
ARRAY
DVDD (3.3V)

IFS/2 + ICODE IFS/2 – ICODE

CODE
AOUT 42 41 AOUT

INTERNAL INTERNAL
50Ÿ 50Ÿ

10836-044

10836-045
AVDD (3.3V)

Figure 26. DAC Output Figure 28. CMOS Input

AVDD (3.3V)

DVDD (3.3V)

REF_CLK REF_CLK

10836-043
10836-048

Figure 27. REF CLK input Figure 29. CMOS Output

Rev. F | Page 16 of 45
Data Sheet AD9914

THEORY OF OPERATION
The AD9914 has five modes of operation. DIGITAL RAMP MODULATION MODE
x Single tone
x Profile modulation
In digital ramp modulation mode, the modulated DDS signal

x Digital ramp modulation (linear sweep)

control parameter is supplied directly from the digital ramp

x Parallel data port modulation

generator (DRG). The ramp generation parameters are

x Programmable modulus mode

controlled through the serial or parallel input/output port.
The ramp generation parameters allow the user to control both
The modes define the data source supplies the DDS with the the rising and falling slopes of the ramp. The upper and lower
signal control parameters: frequency, phase, or amplitude. The boundaries of the ramp, the step size and step rate of the rising
partitioning of the data into different combinations of frequency, portion of the ramp, and the step size and step rate of the falling
phase, and amplitude is established based on the mode and/or portion of the ramp are all programmable.
specific control bits and function pins. The ramp is digitally generated with 32-bit output resolution.
Although the various modes are described independently, they can The 32-bit output of the DRG can be programmed to affect
be enabled simultaneously. This provides an unprecedented level frequency, phase, or amplitude. When programmed for frequency,
of flexibility for generating complex modulation schemes. However, all 32 bits are used. However, when programmed for phase or
to avoid multiple data sources from driving the same DDS signal amplitude, only the 16 MSBs or 12 MSBs, respectively, are used.
control parameter, the device has a built-in priority protocol. The ramp direction (rising or falling) is externally controlled by
In single tone mode, the DDS signal control parameters come the DRCTL pin. An additional pin (DRHOLD) allows the user
directly from the profile programming registers. In digital ramp to suspend the ramp generator in the present state. Note that
modulation mode, the DDS signal control parameters are delivered amplitude control must also be enabled using the OSK enable
by a digital ramp generator. In parallel data port modulation mode, bit in Register CFR1.
the DDS signal control parameters are driven directly into the PARALLEL DATA PORT MODULATION MODE
parallel port.
In parallel data port modulation mode, the modulated DDS signal
The various modulation modes generally operate on only one of control parameter(s) are supplied directly from the 32-bit parallel
the DDS signal control parameters (two in the case of the polar data port. The function pins define how the 32-bit data-word is
modulation format via the parallel data port). The unmodulated applied to the DDS signal control parameters. Formatting of the
DDS signal control parameters are stored in programming registers 32-bit data-word is unsigned binary, regardless of the destination.
and automatically routed to the DDS based on the selected mode.
Parallel Data Clock (SYNC_CLK)
A separate output shift keying (OSK) function is also available.
The AD9914 generates a clock signal on the SYNC_CLK pin
This function employs a separate digital linear ramp generator
that runs at 1/24 of the DAC sample rate (the sample rate of the
that affects only the amplitude parameter of the DDS. The OSK
parallel data port). SYNC_CLK serves as a data clock for the
function has priority over the other data sources that can drive
parallel port.
the DDS amplitude parameter. As such, no other data source
can drive the DDS amplitude when the OSK function is enabled. PROGRAMMABLE MODULUS MODE
SINGLE TONE MODE In programmable modulus mode, the DRG is used as an
auxiliary accumulator to alter the frequency equation of the
In single tone mode, the DDS signal control parameters are
DDS core, making it possible to implement fractions that are
supplied directly from the profile programming registers. A
not restricted to a power of 2 in the denominator. A standard
profile is an independent register that contains the DDS signal
DDS is restricted to powers of 2 as a denominator because the
control parameters. Eight profile registers are available. Note
phase accumulator is a set of bits as wide as the frequency
that the profile pins must select the desired register.
tuning word (FTW).
PROFILE MODULATION MODE When in programmable modulus mode, however, the
Each profile is independently accessible. For FSK, PSK, or ASK frequency equation is:
modulation, use the three external profile pins (PS[2:0]) to select
f0 = (fS)(FTW + A/B)/232
the desired profile. A change in the state of the profile pins with
the next rising edge on SYNC_CLK updates the DDS with the where f0/fS < ½, 0 ≤ FTW < 231, 2 ≤ B ≤ 232 – 1, and A < B.
parameters specified by the selected profile. Therefore, the profile This equation implies a modulus of B × 232 (rather than 232, in
change must meet the setup and hold times to the SYNC_CLK the case of a standard DDS). Furthermore, because B is
rising edge. Note that amplitude control must also be enabled programmable, the result is a DDS with a programmable
using the OSK enable bit in the CFR1 register (0x00[8]). modulus.

Rev. F | Page 17 of 45
AD9914 Data Sheet
When in programmable modulus mode, the 32-bit auxiliary Reducing this fraction to lowest terms yields 3/10; therefore,
accumulator operates in a way that allows it to roll over at a M = 3 and N = 10. FTW is the integer part of (M × 232)/N, or
value other than the full capacity of 232. That is, it operates with (3 × 232)/10, which is 1,288,490,188 (0x4CCCCCCC in 32-bit
a modified modulus based on the programmable value of B. hexadecimal notation). The remainder, Y, of (3 × 232)/10, is (232
With each roll over of the auxiliary accumulator, a value of 1 × 3) − (1,288,490,188 × 10), which is 8. Therefore, Y/N is 8/10,
LSB adds to the current accumulated value of the 32-bit phase which reduces to 4/5. Therefore, A = 4 and B = 5 (0x00000004
accumulator. This behavior changes the modulus of the phase and 0x00000005 in 32-bit hexadecimal notation, respectively).
accumulator to B × 232 (instead of 232), allowing it to synthesize Programming the AD9914 with these values of FTW, A, and B
the desired f0. results in an output frequency that is exactly 3/10 of the system
To determine the programmable modulus mode register values clock frequency.
for FTW, A, and B, the user must first define f0/fS as a ratio of MODE PRIORITY
relatively prime integers, M/N. That is, having converted f0 and The ability to activate each mode independently makes it
fS to integers, M and N, reduce the fraction, M/N, to the lowest possible to have multiple data sources attempting to drive the
terms. Then, divide M × 232 by N. The integer part of this division same DDS signal control parameter (frequency, phase, and
operation is the value of FTW (Register 0x04[31:0]). The amplitude). To avoid contention, the AD9914 has a built-in
remainder, Y, of this division operation is priority system. Table 6 summarizes the priority for each of the
Y = (232 × M) – (FTW × N) DDS modes. The data source column in Table 6 lists data sources
The value of Y facilitates the determination of A and B by taking for a particular DDS signal control parameter in descending
the fraction, Y/N, and reducing it to the lowest terms. Then, the order of precedence. For example, if the profile mode enable bit
numerator of the reduced fraction is A (Register 0x06[31:0]) and the parallel data port enable bit (0x01[23:22]) are set to
and the denominator is the B (Register 0x05[31:0]). Logic 1 and both are programmed to source the frequency
tuning word to DDS output, the profile modulation mode has
For example, synthesizing precisely 300 MHz with a 1 GHz priority over the parallel data port modulation mode.
system clock is not possible with a standard DDS. It is possible,
however, using programmable modulus as follows.
First, express f0/fS as a ratio of integers:
300,000,000/1,000,000,000

Table 6. Data Source Priority

DDS Signal Control Parameters
Priority Data Source Conditions
Highest Priority Programmable modulus If programmable modulus mode is used to output frequency only, no other data source
can control the output frequency in this mode. Note that the DRG is used in conjunction with
programmable modulus mode; therefore, the DRG cannot be used to sweep phase or
amplitude in programmable modulus mode.
If output phase offset control is desired, enable profile mode and use the profile registers
and profile pins accordingly to control output phase adjustment.
If output amplitude control is desired, enable profile mode and use the profile registers
and profile pins accordingly to control output amplitude adjustment. Note that the OSK
enable bit must be set to control the output amplitude.
DRG The digital ramp modulation mode is the next highest priority mode. If the DRG is
enabled to sweep output frequency, phase, or amplitude, the two parameters not being
swept can be controlled independently via the profile mode.
Profiles The profile modulation mode is the next highest priority mode. Profile mode can control
all three parameters independently, if desired.
Lowest Priority Parallel port Parallel data port modulation has the lowest priority but the most flexibility as far as
changing any parameter at the high rate. See the Programming and Function Pins
section.

Rev. F | Page 18 of 45
Data Sheet AD9914

FUNCTIONAL BLOCK DETAIL

DDS CORE The relative phase of the DDS signal can be digitally controlled
The direct digital synthesizer (DDS) block generates a reference by means of a 16-bit phase offset word (POW). The phase offset
signal (sine or cosine based on Register 0x00, Bit 16, the enable is applied prior to the angle to amplitude conversion block internal
sine output bit). The parameters of the reference signal (frequency, to the DDS core. The relative phase offset (Δθ) is given by

2 S§¨ 16 ·
phase, and amplitude) are applied to the DDS at the frequency, POW
© 2 ¹̧
'T
phase offset, and amplitude control inputs, as shown in Figure 30.

360 §¨ 16 ·
The output frequency (fOUT) of the AD9914 is controlled by the POW
frequency tuning word (FTW) at the frequency control input to © 2 ¹̧
the DDS. The relationship among fOUT, FTW, and fSYSCLK is given by

§ FTW · f
where the upper quantity is for the phase offset expressed as
¨ 32
© 2 ¹̧
radian units and the lower quantity as degrees.
f OUT SYSCLK (1)
To find the POW value necessary to develop an arbitrary Δθ,
where FTW is a 32-bit integer ranging in value from 0 to solve the preceding equation for POW and round the result (in
2,147,483,647 (231 − 1), which represents the lower half of the a manner similar to that described previously for finding an
full 32-bit range. This range constitutes frequencies from dc to arbitrary FTW).
Nyquist (that is, ½ fSYSCLK). The relative amplitude of the DDS signal can be digitally scaled
The FTW required to generate a desired value of fOUT is found (relative to full scale) by means of a 12-bit amplitude scale factor
by solving Equation 1 for FTW, as given in Equation 2. (ASF). The amplitude scale value is applied at the output of the
§ § f ··
round ¨ 2 32 ¨¨ OUT ¸¸
angle to amplitude conversion block internal to the DDS core.

¨ ¸¸
The amplitude scale is given by
© © f SYSCLK ¹¹
FTW (2)
ASF
where the round(x) function rounds the argument (the value of 212
20 log §¨ 12 ·
Amplitude Scale (3)
x) to the nearest integer. This is required because the FTW is ASF
constrained to be an integer value. For example, for fOUT = © 2 ¹̧
41 MHz and fSYSCLK = 122.88 MHz, FTW = 1,433,053,867
(0x556AAAAB). where the upper quantity is amplitude expressed as a fraction of
full scale and the lower quantity is expressed in decibels relative
Programming an FTW greater than 231 produces an aliased to full scale.
image that appears at a frequency given by

§1  FTW · f
To find the ASF value necessary for a particular scale factor, solve
¨
© 232 ¹̧
f OUT Equation 3 for ASF and round the result (in a manner similar to
SYSCLK
that described previously for finding an arbitrary FTW).
for FTW ≥ 231 When the AD9914 is programmed to modulate any of the DDS
signal control parameters, the maximum modulation sample
rate is 1/24 fSYSCLK. This means that the modulation signal exhibits
images at multiples of 1/24 fSYSCLK. The impact of these images
must be considered when using the device as a modulator.
DDS SIGNAL CONTROL PARAMETERS

AMPLITUDE 12
CONTROL
PHASE 16
OFFSET
CONTROL MSB ALIGNED
32-BIT
ACCUMULATOR 16 12
32
ANGLE-TO-
17 AMPLITUDE 12 12
FREQUENCY 32 32
DQ
32 17
CONVERSION
CONTROL (SINE OR
R (MSBs) COSINE) TO DAC
10836-026

DDS_CLK ACCUMULATOR
RESET

Figure 30. DDS Block Diagram

Rev. F | Page 19 of 45
AD9914 Data Sheet
12-BIT DAC OUTPUT RECONSTRUCTION FILTER
The AD9914 incorporates an integrated 12-bit, current output The DAC output signal appears as a sinusoid sampled at fS. The
DAC. The output current is delivered as a balanced signal using frequency of the sinusoid is determined by the frequency tuning
two outputs. The use of balanced outputs reduces the potential word (FTW) that appears at the input to the DDS. The DAC
amount of common-mode noise present at the DAC output, output is typically passed through an external reconstruction
offering the advantage of an increased signal-to-noise ratio. An filter that serves to remove the artifacts of the sampling process
external resistor (RSET) connected between the DAC_RSET pin and other spurs outside the filter bandwidth.
and AGND establishes the reference current. The recommended Because the DAC constitutes a sampled system, the output must
value of RSET is 3.3 kΩ. be filtered so that the analog waveform accurately represents the
Attention must be paid to the load termination to keep the digital samples supplied to the DAC input. The unfiltered DAC
output voltage within the specified compliance range; voltages output contains the desired baseband signal, which extends from
developed beyond this range cause excessive distortion and can dc to the Nyquist frequency (fS/2). It also contains images of the
damage the DAC output circuitry. baseband signal that theoretically extend to infinity. Notice that
the odd numbered images (shown in Figure 31) are mirror
DAC CALIBRATION OUTPUT
images of the baseband signal. Furthermore, the entire DAC
The DAC CAL enable bit in the CFR4 control register (0x03[24]) output spectrum is affected by a sin(x)/x response, which is
must be manually set and then cleared after each power-up and caused by the sample-and-hold nature of the DAC output signal.
every time the REF CLK or internal system clock is changed.
This initiates an internal calibration routine to optimize the For applications using the fundamental frequency of the DAC
setup and hold times for internal DAC timing. Failure to output, the response of the reconstruction filter must preserve
calibrate may degrade performance and even result in loss of the baseband signal (Image 0), while completely rejecting all other
functionality. The length of time to calibrate the DAC clock is images. However, a practical filter implementation typically
calculated from the following equation: exhibits a relatively flat pass band that covers the desired output
frequency plus 20%, rolls off as steeply as possible, and then
469,632 maintains significant (though not complete) rejection of the
t CAL
fS remaining images. Depending on how close unwanted spurs are
to the desired signal, a third-, fifth-, or seventh-order elliptic
low-pass filter is common.
Some applications operate from an image above the Nyquist
frequency, and those applications use a band-pass filter instead
of a low-pass filter. The design of the reconstruction filter has a
significant impact on the overall signal performance. Therefore,
good filter design and implementation techniques are important
for obtaining the best possible jitter results.
MAGNITUDE
(dB)
IMAGE 0 IMAGE 1 IMAGE 2 IMAGE 3 IMAGE 4
0

–20
PRIMARY FILTER
–40 SIGNAL RESPONSE SIN(x)/x
–60 ENVELOPE

–80 SPURS

–100 f
10836-027

fs/2 fs 3fs/2 2fs 5fs/2

BASE BAND

Figure 31. DAC Spectrum vs. Reconstruction Filter Response

Rev. F | Page 20 of 45
Data Sheet AD9914
CLOCK INPUT (REF_CLK/REF_CLK) The REF_CLK/REF_CLK input resistance is ~2.5 kΩ differential
REF_CLK/REF_CLK Overview (~1.2 kΩ single-ended). Most signal sources have relatively low
output impedances. The REF_CLK/REF_CLK input resistance is
The AD9914 supports a number of options for producing the
relatively high; therefore, the effect on the termination impedance
internal SYSCLK signal (that is, the DAC sample clock) via the
is negligible and can usually be chosen to be the same as the output
REF_CLK/REF_CLK input pins. The REF_CLK input can be
impedance of the signal source. The bottom two examples in
driven directly from a differential or single-ended source. There Figure 33 assume a signal source with a 50 Ω output impedance.
is also an internal phase-locked loop (PLL) multiplier that can
0.1µF
be independently enabled. However, the PLL limits the SYSCLK 55 REF_CLK
PECL,
signal between 2.4 GHz and 2.5 GHz operation. A differential DIFFERENTIAL SOURCE, LVPECL,
DIFFERENTIAL INPUT OR TERMINATION
signal is recommended when the PLL is bypassed. A block LVDS
DRIVER
diagram of the REF_CLK functionality is shown in Figure 32. 54 REF_CLK
0.1µF
Figure 32 also shows how the CFR3 control bits are associated
with specific functional blocks.
BALUN 0.1µF
LOOP_FILTER
(1:1) 55 REF_CLK
58
SINGLE-ENDED SOURCE,
DIFFERENTIAL INPUT 50Ÿ
PLL ENABLE
DOUBLER ENABLE CFR3[18]
CFR3[19] 54 REF_CLK
0.1µF
DOUBLER
CLOCK EDGE
CFR3[16]
0.1µF
ENABLE LOOP
FILTER 55 REF_CLK
×2 1
IN PLL OUT 1 SYSCLK SINGLE-ENDED SOURCE,
÷ 1, 2, 4, 8 0 SINGLE-ENDED INPUT 50Ÿ
CHARGE 0
PUMP DIVIDE

10836-029
54 REF_CLK
2INPUT DIVIDER 0.1µF
REF_CLK 2 7
RESET CFR3[22] N
55
INPUT DIVIDER RATIO ICP CFR3[15:8] Figure 33. Direct Connection Diagram
54 CFR3[21:20] CFR3[5:3]
10836-028

REF_CLK Phase-Locked Loop (PLL) Multiplier

An internal PLL provides the option to use a reference clock
Figure 32. REF_CLK Block Diagram
frequency that is significantly lower than the system clock
The PLL enable bit chooses between the PLL path or the direct frequency. The PLL supports a wide range of programmable
input path. When the direct input path is selected, even frequency multiplication factors (20× to 510×) as well as a
the REF_CLK/REF_CLK pins must be driven by an external programmable charge pump current and external loop filter
signal source (single-ended or differential). Input frequencies components (connected via the PLL LOOP_FILTER pin). These
up to 3.5 GHz are supported. features add an extra layer of flexibility to the PLL, allowing
Direct Driven REF_CLK/REF_CLK optimization of phase noise performance and flexibility in
frequency plan development. The PLL is also equipped with a
With a differential signal source, the REF_CLK/REF_CLK pins PLL lock bit indicator (0x1B[24]).
are driven with complementary signals and ac-coupled with 0.1 µF
capacitors. With a single-ended signal source, either a single- The PLL output frequency range (fSYSCLK) is constrained to the
ended-to-differential conversion can be employed or the range of 2.4 GHz ≤ fSYSCLK ≤ 2.5 GHz by the internal VCO.
REF_CLK input can be driven single-ended directly. In either VCO Calibration
case, 0.1 µF capacitors ac couples both REF_CLK/ REF_CLK When using the PLL to generate the system clock, VCO calibration
pins to avoid disturbing the internal dc bias voltage of ~1.35 V. is required to tune the VCO appropriately and achieve good
See Figure 33 for more details. performance. When the reference input signal is stable, the
VCO cal enable bit in the CFR1 register, 0x00[24], must be
asserted. Subsequent VCO calibrations require that the VCO
calibration bit be cleared prior to initiating another VCO
calibration. VCO calibration must occur before DAC calibration
to ensure optimal performance and functionality.

Rev. F | Page 21 of 45
AD9914 Data Sheet
PLL Charge Pump/Total Feedback Divider
CZ = 560pF (RECOMMENDED)
The charge pump current (ICP) value is automatically chosen via 0.47µF
REF LOOP_FILTER
the VCO calibration process and N value (N = 10 to 255) stored 59 58

in Feedback Divider N[7:0] in the CFR3 register (0x02[15:8]). N CP

50pF RPZ (3.5kŸ)
values below 10 must be avoided.
Note that the total PLL multiplication value for the PLL is always REFCLK PLL
2N due to the fixed divide by 2 element in the feedback path. PLL IN
This is shown in Figure 34. This fixed divide by 2 element forces PFD CP VCO PLL OUT

only even PLL multiplication.

10836-030
÷N ÷2
To manually override the charge pump current value, the manual
ICP selection bit in CFR3 (0x02[6]) must be set to Logic 1. This Figure 34. REF CLK PLL External Loop Filter
provides the user with additional flexibility to optimize the PLL
PLL LOCK INDICATION
performance. Table 7 lists the bit settings vs. the nominal charge
pump current. When the PLL is in use, the PLL lock bit (0x1B[24])provides an
active high indication that the PLL has locked to the REF CLK
Table 7. PLL Charge Pump Current input signal.
ICP Bits (CFR3[5:3]) Charge Pump Current, ICP (μA)
OUTPUT SHIFT KEYING (OSK)
000 125
001 250 The OSK function (see Figure 35) allows the user to control the
010 375 output signal amplitude of the DDS. The amplitude data generated
011 500 (default) by the OSK block has priority over any other functional block
100 625
that is programmed to deliver amplitude data to the DDS.
101 750
Therefore, the OSK data source, when enabled, overrides all
110 875
other amplitude data sources.
111 1000 The operation of the OSK function is governed by two CFR1
register bits, OSK enable (0x00[8]) and external OSK enable
Table 8. N Divider vs. Charge Pump Current (0x00[9]), the external OSK pin, the profile pins, and the 12 bits
Recommended Charge Pump of amplitude scale factor found in one of eight profile registers.
N Divider Range Current, ICP (μA) The profile pins select the profile register containing the desired
10 to 15 125 amplitude scale factor.
16 to 23 250
24 to 35 375
The primary control for the OSK block is the OSK enable bit
36 to 43 500
(0x00[8]). When the OSK function is disabled, the OSK input
controls and OSK pin are ignored.
44 to 55 625
56 to 63 750 The OSK pin functionality depends on the state of the external
64 to 79 875 OSK enable bit and the OSK enable bit. When both bits are set
80 to 100 1000 to Logic 1 and the OSK pin is Logic 0, the output amplitude is
PLL Loop Filter Components forced to 0; otherwise, if the OSK pin is Logic 1, the output
amplitude is set by the amplitude scale factor value in one of
The loop filter is mostly internal to the device, as shown in eight profile registers depending on the profile pin selection.
Figure 34. The recommended external capacitor value is 560 pF.
PS0 PS1 PS2 OSK
Because CP and RPZ are integrated, it is not recommended to 25 26 27 66

adjust the loop bandwidth via the external capacitor value. The
better option is to adjust the charge pump current even though OSK ENABLE
it is a coarse adjustment. EXTERNAL
OSK ENABLE
TO DDS
For example, suppose the PLL is manually programmed such AMPLITUDE SCALE 12 OSK 12 AMPLITUDE
FACTOR (1 OF 8 CONTROLLER CONTROL
that ICP = 375 μA, KV = 60 MHz/V, and N = 25. This produces a SELECTED PROFILE PARAMETER
REGISTERS [27:16])
loop bandwidth of approximately 250 kHz.
10836-031

DDS CLOCK
Figure 35. OSK Block Diagram

Rev. F | Page 22 of 45
Data Sheet AD9914
DIGITAL RAMP GENERATOR (DRG) The output of the DRG is a 32-bit unsigned data bus that can be
DRG Overview routed to any one of the three DDS signal control parameters, as
controlled by the two digital ramp destination bits in Control
To sweep phase, frequency, or amplitude from a defined start
Function Register 2 according to Table 9. The 32-bit output bus
point to a defined endpoint, a completely digital ramp generator
is MSB-aligned with the 32-bit frequency parameter, the 16-bit
is included in the AD9914. The DRG makes use of eight control
phase parameter, or the 12-bit amplitude parameter, as defined
register bits, three external pins, and five 32-bit registers (see
by the destination bits. When the destination is phase or amplitude,
Figure 36).
the unused LSBs are ignored.

DRHOLD

DROVER
DRCTL
Table 9. Digital Ramp Destination
63 64 65 Digital Ramp DDS Signal
Destination Bits Control Bits Assigned to
(CFR2[21:20]) Parameter DDS Parameter
DIGITAL RAMP ENABLE
2 00 Frequency 31:0
DIGITAL RAMP DESTINATION
01 Phase 31:18
2
DIGITAL RAMP NO-DWELL 1x1 Amplitude 31:20
LOAD LRR AT I/O_UPDATE
1
CLEAR DIGITAL x = don’t care.
RAMP ACCUMULATOR
AUTOCLEAR DIGITAL The ramp characteristics of the DRG are fully programmable.
RAMP ACCUMULATOR
32
This includes the upper and lower ramp limits, and independent
DIGITAL RAMP LOWER LIMIT REGISTER DIGITAL 32 control of the step size and step rate for both the positive and
RAMP
32 GENERATOR TO DDS negative slope characteristics of the ramp. A detailed block
DIGITAL RAMP UPPER LIMIT REGISTER SIGNAL
CONTROL diagram of the DRG is shown in Figure 37.
PARAMETER
RISING DIGITAL RAMP STEP
32 The direction of the ramping function is controlled by the
SIZE REGISTER
DRCTL pin. Logic 0 on this pin causes the DRG to ramp with a
32
FALLING DIGITAL RAMP STEP
SIZE REGISTER
negative slope, whereas Logic 1 causes the DRG to ramp with a
32
positive slope.
DIGITAL RAMP RATE REGISTER
The DRG also supports a hold feature controlled via the DRHOLD
pin. When this pin is set to Logic 1, the DRG is stalled at the
10836-032

last state; otherwise, the DRG operates normally. The DDS

DDS CLOCK
signal control parameters that are not the destination of the
Figure 36. Digital Ramp Block Diagram
DRG are taken from the active profile.
The primary control for the DRG is the digital ramp enable bit
(0x01[19]). When disabled, the other DRG input controls are
ignored and the internal clocks are shut down to conserve power.

DIGITAL RAMP ACCUMULATOR

32
DECREMENT STEP SIZE 0 32 32
32
INCREMENT STEP SIZE 1
TO DDS
32 32 SIGNAL
D Q LIMIT CONTROL CONTROL
PARAMETER
DRCTL 63
R 32 32

UPPER LOWER
LIMIT LIMIT
16
NEGATIVE SLOPE RATE 0 16
16
POSITIVE SLOPE RATE 1 2
NO-DWELL NO DWELL
ACCUMULATOR CONTROL
RESET
CONTROL CLEAR DIGITAL RAMP ACCUMULATOR
LOGIC
LOAD
PRESET . ACC
AUTOCLEAR DIGITAL RAMP
LOAD LRR AT I/O_UPDATE CONTROL LOAD
LOGIC
Q
DRHOLD 64 DIGITAL
10836-033

RAMP
DDS CLOCK TIMER

Figure 37. Digital Ramp Generator Detail

Rev. F | Page 23 of 45
AD9914 Data Sheet
DRG Slope Control Note that the frequency units are the same as those that represent
The core of the DRG is a 32-bit accumulator clocked by a fSYSCLK (MHz, for example). The amplitude units are the same as
programmable timer. The time base for the timer is the DDS those that represent IFS, the full-scale output current of the DAC
clock, which operates at 1/24 fSYSCLK. The timer establishes the (mA, for example).
interval between successive updates of the accumulator. The The phase and amplitude step size equations yield the average
positive (+Δt) and negative (−Δt) slope step intervals are step size. Although the step size accumulates with 32-bit precision,
independently programmable as given by the phase or amplitude destination exhibits only 16 bits or 12 bits,

 't
24P respectively. Therefore, at the destination, the actual phase or
amplitude step is the accumulated 32-bit value truncated to
f SYSCLK
16 bits or 12 bits, respectively.
 't
24 N
As described previously, the step interval is controlled by a
f SYSCLK 16-bit programmable timer. There are three events that can
where P and N are the two 16-bit values stored in the 32-bit digital cause this timer to be reloaded prior to the expiration. One
ramp rate register and control the step interval. N defines the step event occurs when the digital ramp enable bit transitions from
interval of the negative slope portion of the ramp. P defines the step cleared to set, followed by an input/output update. A second
interval of the positive slope portion of the ramp. event is a change of state in the DRCTL pin. The third event is
enabled using the load LRR at input/output update bit
The step size of the positive (STEPP) and negative (STEPN) slope
(0x00[15]).
portions of the ramp are 32-bit values programmed into the 32-bit
rising and falling digital ramp step size registers (0x06 and 0x07). DRG Limit Control
Program each of the step sizes as an unsigned integer (the hardware The ramp accumulator is followed by limit control logic that
automatically interprets STEPN as a negative value). The enforces an upper and lower boundary on the output of the
relationship between the 32-bit step size values and actual units ramp generator. Under no circumstances does the output of the
of frequency, phase, or amplitude depend on the digital ramp DRG exceed the programmed limit values while the DRG is
destination bits. Calculate the actual frequency, phase, or amplitude enabled. The limits are set through the 64-bit digital ramp limit
step size by substituting STEPN or STEPP for M in the following register. Note that the upper limit value must be greater than the
equations as required: lower limit value to ensure normal operation.
§ M ·f
¨ 32 SYSCLK
DRG Accumulator Clear
© 2 ¹̧
Frequency Step

SM
The ramp accumulator can be cleared (that is, reset to 0) under
program control. When the ramp accumulator is cleared, it forces
Phase Step
231 (radians) the DRG output to the lower limit programmed into the digital
ramp limit register.
45M
Phase Step With the limit control block embedded in the feedback path of the
229 (degrees) accumulator, resetting the accumulator is equivalent to presetting
§ M ·I
¨ 32 FS
it to the lower limit value.
© 2 ¹̧
Amplitude Step

Rev. F | Page 24 of 45
Data Sheet AD9914
P DDS CLOCK CYCLES N DDS CLOCK CYCLES 1 DDS CLOCK CYCLE
NEGATIVE
STEP SIZE
POSITIVE
STEP SIZE
+ǻt –ǻt UPPER LIMIT

DRG OUTPUT

LOWER LIMIT
DROVER

DIGITAL RAMP ENABLE

RELEASE
DRCTL

CLEAR

CLEAR
AUTO
DRHOLD

CLEAR DIGITAL
RAMP ACCUMULATOR

AUTOCLEAR DIGITAL
RAMP ACCUMULATOR

I/O_UPDATE

10836-034
1 2 3 4 5 6 7 8 9 11 13
10 12

Figure 38. Normal Ramp Generation

Normal Ramp Generation Event 4—DRCTL transitions to Logic 0 to initiate a negative slope
Normal ramp generation implies that both no-dwell bits are at the DRG output. In this example, the DRCTL pin is held long
cleared (see the No-Dwell Ramp Generation section for details). enough to cause the DRG to reach the programmed lower limit.
In Figure 38, a sample ramp waveform is depicted with the The DRG remains at the lower limit until DRCTL = 1, or until the
required control signals. The top trace is the DRG output. The lower limit is reprogrammed to a lower value. In the latter case,
next trace down is the status of the DROVER output pin (assuming the DRG immediately resumes the previous negative slope profile.
that the DRG over output enable bit is set). The remaining traces Event 5—DRCTL transitions to Logic 1 for the second time,
are control bits and control pins. The pertinent ramp parameters initiating a second positive slope.
are also identified (upper and lower limits plus step size and Δt Event 6—The positive slope profile is interrupted by DRHOLD
for the positive and negative slopes). Along the bottom, circled transitioning to Logic 1. This stalls the ramp accumulator and
numbers identify specific events. These events are referred to by freezes the DRG output at the last value.
number (Event 1 and so on) in the following paragraphs.
Event 7—DRHOLD transitions to Logic 0, releasing the ramp
In this example, the positive and negative slopes of the ramp are accumulator and reinstating the previous positive slope profile.
different to demonstrate the flexibility of the DRG. The parameters
of both slopes can be programmed to make the positive and Event 8—The clear digital ramp accumulator bit is set, which
negative slopes the same. has no effect on the DRG because the bit is not effective until an
input/output update is issued.
Event 1—The digital ramp enable bit is set, which has no effect
on the DRG output because the bit is not effective until an Event 9—An input/output update registers that the clear digital
input/output update occurs. ramp accumulator bit is set, resetting the ramp accumulator and
forcing the DRG output to the programmed lower limit. The DRG
Event 2—An input/output update registers the digital ramp output remains at the lower limit until the clear condition is
enable bit. If DRCTL = 1 is in effect (the gray portion of the removed.
DRCTL trace), the DRG output immediately begins a positive
slope (the gray portion of the DRG output trace). Otherwise, if Event 10—The clear digital ramp accumulator bit is cleared,
DRCTL = 0, the DRG output is initialized to the lower limit. which has no effect on the DRG output because the bit is not
effective until an input/output update is issued.
Event 3—DRCTL transitions to Logic 1 to initiate a positive
slope at the DRG output. In this example, the DRCTL pin is Event 11—An input/output update registers that the clear
held long enough to cause the DRG to reach the programmed digital ramp accumulator bit is cleared, releasing the ramp
upper limit. The DRG remains at the upper limit until the ramp accumulator; and the previous positive slope profile restarts.
accumulator is cleared (DRCTL = 0) or the upper limit is Event 12—The autoclear digital ramp accumulator bit is set,
reprogrammed to a higher value. In the latter case, the DRG which has no effect on the DRG output because the bit is not
immediately resumes the previous positive slope profile. effective until an input/output update is issued.

Rev. F | Page 25 of 45
AD9914 Data Sheet
Event 13—An input/output update registers that the autoclear tion between the limits. Likewise, if the DRG output is in the
digital ramp accumulator bit is set, resetting the ramp accumulator. midst of a negative slope and the DRCTL pin transitions from
However, with an automatic clear, the ramp accumulator is held Logic 0 to Logic 1, the DRG immediately switches to the positive
in reset for only a single DDS clock cycle. This forces the DRG slope parameters and resumes oscillation between the limits.
output to the lower limit, but the ramp accumulator is immedi- When both no-dwell bits are set, the DROVER signal produces
ately made available for normal operation. In this example, the a positive pulse (two cycles of the DDS clock) each time the DRG
DRCTL pin remains Logic 1; therefore, the DRG output restarts output reaches either of the programmed limits (assuming that
the previous positive ramp profile. the DRG over output enable bit (0x01[13]) is set).
No-Dwell Ramp Generation A no-dwell high DRG output waveform is shown in Figure 39.
The two no-dwell high and no-dwell low bits (0x01[18:17]) in The waveform diagram assumes that the digital ramp no-dwell
CFR2 add to the flexibility of the DRG capabilities. During normal high bit is set and has been registered by an input/output
ramp generation, when the DRG output reaches the programmed update. The status of the DROVER pin is also shown with the
upper or lower limit, it simply remains at the limit until the assumption that the DRG over output enable bit has been set.
operating parameters dictate otherwise. However, during no-dwell The circled numbers in Figure 39 indicate specific events, which
operation, the DRG output does not necessarily remain at the limit. are explained as follows:
For example, if the digital ramp no-dwell high bit is set when the
DRG reaches the upper limit, it automatically (and immediately) Event 1—Indicates the instant that an input/output update
snaps to the lower limit (that is, it does not ramp back to the lower registers that the digital ramp enable bit is set.
limit; it jumps to the lower limit). Likewise, when the digital ramp Event 2—DRCTL transitions to Logic 1, initiating a positive
no-dwell low bit is set, and the DRG reaches the lower limit, it slope at the DRG output.
automatically (and immediately) snaps to the upper limit. Event 3—DRCTL transitions to Logic 0, which has no effect on
During no-dwell operation, the DRCTL pin is monitored for state the DRG output.
transitions only; that is, the static logic level is immaterial. Event 4—Because the digital ramp no-dwell high bit is set, the
During no-dwell high operation, a positive transition of the moment that the DRG output reaches the upper limit, it imme-
DRCTL pin initiates a positive slope ramp, which continues diately switches to the lower limit, where it remains until the
uninterrupted (regardless of any further activity on the DRCTL next Logic 0 to Logic 1 transition of DRCTL.
pin) until the upper limit is reached. Event 5—DRCTL transitions from Logic 0 to Logic 1, which
During no-dwell low operation, a negative transition of the DRCTL restarts a positive slope ramp.
pin initiates a negative slope ramp, which continues uninterrupted Event 6 and Event 7—DRCTL transitions are ignored until the
(regardless of any further activity on the DRCTL pin) until the DRG output reaches the programmed upper limit.
lower limit is reached.
Event 8—Because the digital ramp no-dwell high bit is set, the
Setting both no-dwell bits invokes a continuous ramping mode moment that the DRG output reaches the upper limit, it immedi-
of operation; that is, the DRG output automatically oscillates ately switches to the lower limit, where it remains until the next
between the two limits using the programmed slope parameters. Logic 0 to Logic 1 transition of DRCTL.
Furthermore, the function of the DRCTL pin is slightly different.
Instead of controlling the initiation of the ramp sequence, it Operation with the digital ramp no-dwell low bit set (instead of
only serves to change the direction of the ramp; that is, if the the digital ramp no-dwell high bit) is similar, except that the DRG
DRG output is in the midst of a positive slope and the DRCTL output ramps in the negative direction on a Logic 1 to Logic 0
pin transitions from Logic 1 to Logic 0, the DRG immediately transition of DRCTL and jumps to the upper limit upon
switches to the negative slope parameters and resumes oscilla- reaching the lower limit.
P DDS CLOCK CYCLES

POSITIVE
STEP SIZE
+ǻt UPPER LIMIT

DRG OUTPUT

LOWER LIMIT
DROVER

DRCTL
10836-035

1 2 3 4 5 6 7 8
Figure 39. No-Dwell High Ramp Generation

Rev. F | Page 26 of 45
Data Sheet AD9914
DROVER Pin POWER-DOWN CONTROL
The DROVER pin provides an external signal to indicate the status The AD9914 offers the ability to independently power down
of the DRG. Specifically, when the DRG output is at either of three specific sections of the device. Power-down functionality
the programmed limits, the DROVER pin is Logic 1; otherwise, applies to the following:
x
it is Logic 0. In the special case of both no-dwell bits set, the
Digital core
x
DROVER pin pulses positive for two DDS clock cycles each
DAC
x
time the DRG output reaches either of the programmed limits.
Input REF CLK clock circuitry
Frequency Jumping Capability in DRG Mode
A power-down of the digital core disables the ability to update
Another feature of the AD9914 allows the user to skip a predefined
the serial/parallel input/output port. However, the digital
range of frequencies during a normal sweep. The frequency jump
power-down bit (0x00[7]) can still be cleared to prevent the
enable bit in CFR2 (0x01[14]) enables this functionality. When
possibility of a nonrecoverable state.
this bit is set, the sweeping logic monitors the instantaneous
frequency. When it reaches the frequency point defined in the Software power-down is controlled via three independent
lower frequency jump register (0x09) on the next accumulation power-down bits in CFR1. Software control requires that the
cycle, instead of accumulating a delta tuning word as in normal EXT_PWR_DWN pin be forced to a Logic 0 state. In this case,
sweeping, it skips directly to the frequency value set in the upper setting the desired power-down bits (0x00[7:5]) via the serial
frequency jump register (0x0A), and vice versa. Figure 40 shows input/output port powers down the associated functional block,
how this feature works. whereas clearing the bits restores the function.
A second frequency jump can also be allowed if the frequency Alternatively, all three functions can be simultaneously powered
jump registers are reprogrammed before the sweeping is complete. down via external hardware control through the EXT_PWR_DWN
pin. When this pin is forced to Logic 1, all four circuit blocks are
The following rules apply when this feature is enabled.
x
powered down regardless of the state of the power-down bits;
The frequency jump values must lie between the lower that is, the independent power-down bits in CFR1 are ignored
limit and upper limit of the frequency sweep range.
x
and overridden when EXT_PWR_DWN is Logic 1.
The lower frequency jump register value must be lower
Based on the state of the external power-down control bit, the
than that of the upper frequency jump register value.
EXT_PWR_DWN pin produces either a full power-down or a
FREQUENCY fast recovery power-down. The fast recovery power-down mode
UPPER LIMIT maintains power to the DAC bias circuitry and the PLL, VCO,
and input clock circuitry. Although the fast recovery power-down
0x09 does not conserve as much power as the full power-down, it allows
0x0A
the device to awaken very quickly from the power-down state.
LOWER LIMIT
10836-036

t
Figure 40. Frequency vs. Time

Rev. F | Page 27 of 45
AD9914 Data Sheet

PROGRAMMING AND FUNCTION PINS

The AD9914 is equipped with a 32-bit parallel port. The 32-bit The state of the external function pins (F0 to F3) determines
port is for programming the internal registers of the device in how the 32-bit parallel port is configured. Pin 28 to Pin 31 are
either serial mode or parallel mode as well as allowing for direct the function pins. Refer to Table 10 for possible configurations.
modulation control of frequency (FTW), phase (POW), and Note that the OSK enable bit, CFR1[8], must be set to enable
amplitude (AMP). amplitude control, as shown in Table 10.
Table 10. Parallel Port Configurations
Function Pins, 32-Bit Parallel Port Pin Assignment
F[3:0]1 Mode Description Bits[31:24] 2
Bits[23:16]3 Bits[15:8]4 Bits[7:0]5
0000 Parallel programming mode Data[15:8] Data[7:0] Address[7:0] Controls writes, reads, and 8-bit
(optional) or 16-bit data-word. See the
Parallel Programming section for
details.
0001 Serial programming mode Not used Not used Not used Controls SCLK, SDIO, SDO, CS,
and SYNCIO. See the Serial
Programming section for details.
0010 Full 32 bits of direct frequency FTW[31:24] FTW[23:16] FTW[15:8] FTW[7:0]
tuning word control. MSB and LSB
aligned to parallel port pins
0011 Full 32 bits of direct frequency FTW[15:8] FTW[7:0] FTW[31:24] FTW[23:16]
tuning word control with different
parallel port pin assignments
0100 Full 16 bits of direct phase offset POW[15:8] POW[7:0] AMP[11:8] AMP[7:0]
control and full 12 bits of direct
amplitude control
0101 Full 12 bits of direct amplitude AMP[11:8] AMP[7:0] POW[15:8] POW[7:0]
control and full 16 bits of direct
phase offset control
0110 24 bits of partial FTW control and FTW[31:24] FTW[23:16] FTW[15:8] AMP[15:8]
8 bits of partial amplitude control
0111 24 bits of partial FTW control and FTW[31:24] FTW[23:16] FTW[15:8] POW[15:8]
8 bits of partial phase offset control
1000 24 bits of partial FTW control and FTW[31:24] FTW[23:16] FTW[15:8] AMP[7:0]
8 bits of partial amplitude control
1001 24 bits of partial FTW control and FTW[31:24] FTW[23:16] FTW[15:8] POW[7:0]
8 bits of partial phase offset control
1010 24 bits of partial FTW control and FTW[23:16] FTW[15:8] FTW[7:0] AMP[15:8]
8 bits of partial amplitude control
1011 24 bits of partial FTW control and FTW[23:16] FTW[15:8] FTW[7:0] POW[15:8]
8 bits of partial phase offset control
1100 24 bits of partial FTW control and FTW[23:16] FTW[15:8] FTW[7:0] AMP[7:0]
8 bits of partial amplitude control
1101 24 bits of partial FTW control and FTW[23:16] FTW[15:8] FTW[7:0] POW[7:0]
8 bits of partial phase offset control
1110 Not used Not used Not used Not used
1111 Not used Not used Not used Not used
1
Pin 31 to Pin 28.
2
Pin 68 to Pin 72, Pin 75 to 77.
3
Pin 78 to Pin 81, Pin 87, Pin 88, Pin 1, Pin 2.
4
Pin 3 to Pin 5, Pin 8 to Pin 12.
5
Pin 13 to Pin 15, Pin 18 to Pin 22.

Rev. F | Page 28 of 45
Data Sheet AD9914
4 F[3:0]
FUNCTION DECODE
PINS

DDS
DIRECT MODES 32
FTW FREQUENCY
32 BITS[31:0] 32 32 16
PARALLEL ROUTING
DQ POW PHASE
PORT PINS LOGIC
12
SYNC_CLK CK AMP AMPLITUDE

32
FUNCTION PINS AND DIRECT MODE
BITS[31:0] VS. FTW, POW, AMP PARALLEL MODE OSK ENABLE SYSTEM
PARALLEL CLOCK
F[3:0] BITS[31:24] BITS[23:16] BITS[15:8] BITS[7:0] CONTROL
27 8 BITS[31:24] PROGRAMMING
0000 PARALLEL MODE D[15:8] REGISTERS
8 BITS[23:16]
0001 SERIAL MODE D[7:0]
8 BITS[15:8]
DIRECT MODE A[7:0]
0010 FTW[31:24] FTW[23:16] FTW[15:8] FTW[7:0] BIT 2 IO_UPDATE
WR
0011 FTW[15:8] FTW[7:0] FTW[31:24] FTW[23:16] BIT 1
RD
0100 POW[15:8] POW[7:0] AMP[11:8] AMP[7:0] BIT 0
16 BITS/8 BITS
0101 AMP[11:8] AMP[7:0] POW[15:8] POW[7:0]

0110 FTW[31:24] FTW[23:16] FTW[15:8] AMP[15:8]

0111 FTW[31:24] FTW[23:16] FTW[15:8] POW[15:8] SERIAL MODE

SERIAL
1000 FTW[31:24] FTW[23:16] FTW[15:8] AMP[7:0] CONTROL
5 BIT 4
1001 FTW[31:24] FTW[23:16] FTW[15:8] POW[7:0] SYNCIO
1010 FTW[23:16] FTW[15:8] FTW[7:0] AMP[15:8] BIT 3
SDO
1011 FTW[23:16] FTW[15:8] FTW[7:0] POW[15:8] BIT 2
SDIO
1100 FTW[23:16] FTW[15:8] FTW[7:0] AMP[7:0] BIT 1
SCLK
1101 FTW[23:16] FTW[15:8] FTW[7:0] POW[7:0] BIT 0
CS

10836-046
NOTES
1. AMP[11:0] CONTROLS AMPLITUDE. AMP[15:12] UNUSED.

Figure 41. Parallel Port Block Diagram

The 32-pin parallel port of the AD9914 works in conjunction allows the user to write to the device registers at rates of up to
with an independent set of four function pins that control the 200 MBps using 16-bit data (or 100 MBps using 8-bit data).
functionality of the parallel port. The 32 pins of the parallel port The serial mode is in effect when the logic levels applied to the
constitute a 32-bit word designated by Bits[31:0] (31 indicating function pins are F[3:0] = 0001. This allows the parallel port to
the most significant bit (MSB) and 0 indicating the least significant function as a serial interface providing access to all of the device
bit (LSB)), with the four function pins designated as F[3:0]. The programming registers. In this mode, only five pins of the 32-pin
relationship between the function pins, the 32-pin parallel port, parallel port are functional (Bits[4:0]). These pins provide chip
the internal programming registers, and the DDS control select (CS), serial clock (SCLK), and input/output synchronization
parameters (frequency, phase, and amplitude) is illustrated in
(SYNCIO) functionality for the serial interface, as well as two
Figure 41. Note that the parallel port operates in three different
serial data lines (SDO and SDIO). The serial mode supports
modes as defined by the function pins.
data rates of up to 80 Mbps.
The parallel mode is in effect when the logic levels applied to
When the logic levels applied to the function pins are F[3:0] =
the function pins are F[3:0] = 0000. This allows the parallel port
0010 to 1101 (note that 1110 and 1111 are unused), the parallel
to function as a parallel interface providing access to all of the
port functions as a high speed interface with direct access to the
device programming registers. In parallel mode, the 32-pin port
32-bit frequency, 16-bit phase, and 12-bit amplitude parameters
(Bits[31:0]) is subdivided into three groups with Bits[31:16]
of the DDS core. The table in Figure 41 shows the segmentation
constituting 16 data bits, Bits[15:8] constituting eight address
of the 32-pin parallel port by identifying Bits[31:0] with the
bits, and Bits[2:0] constituting three control bits. The address
frequency (FTW[31:0]), phase (POW[15:0]), and amplitude
bits target a specific device register, whereas the data bits
(AMP[15:0]) parameters of the DDS. Note, however, that
constitute the register content. The control bits establish read or
although AMP[15:0] indicate 16-bit resolution, the actual
write functionality as well as set the width of the data bus. That
amplitude resolution is 12 bits. Therefore, only AMP[11:0]
is, the user can select whether the data bus spans 16 bits
provide amplitude control (that is, AMP[15:12] are not used).
(Bits[31:16]) or eight bits (Bits[23:16]). The parallel mode

Rev. F | Page 29 of 45
AD9914 Data Sheet
Furthermore, to make use of amplitude control, the user must When this bit is set to Logic 1, the parallel port operates without
be sure to program the OSK enable bit in the CFR1 register the need for an input/output update. When this bit is Logic 0,
(0x00[8]) to Logic 1. however, the device delivers the parallel port data to the
The combination of the F[3:0] pins and Bits[31:0] provides the appropriate registers (FTW, POW, AMP), but not to the DDS
AD9914 with unprecedented modulation capability by allowing core. Data does not transfer to the DDS core until the user
the user direct control of the DDS parameters (frequency, phase, asserts the IO_UPDATE pin.
amplitude, or various combinations thereof). Furthermore, the For example, suppose that an application requires frequency and
parallel port operates at a sample rate equal to 1/24 of the system amplitude modulation with full 32-bit frequency resolution and
sample clock. This allows for updates of the DDS parameters at full 12-bit amplitude resolution. Note that none of the F[3:0]
rates of up to 145 MSPS (assuming a 3.5 GHz system clock) pin combinations supports such modulation capability directly.
allowing the AD9914 to accommodate applications with To circumvent this problem, set the parallel port streaming
wideband modulation requirements. enable bit (0x00[17]) to Logic 0. This allows for the use of two
Be aware that the frequency, phase, and amplitude changes applied direct mode cycles of the 32-pin parallel port, each with a
at the parallel port travel to the DDS core over different paths, different function pin setting, without affecting the DDS core
experiencing different propagation times (latency). Therefore, until assertion of the IO_UPDATE pin. That is, during the first
modulating more than one DDS parameter necessitates setting direct mode cycle, set the function pins to F[3:0] = 0010, which
the matched latency enable bit in the CFR2 register (0x01[15]) routes all 32 bits to the FTW register (frequency). On the next
of the device, which equalizes the latency of each DDS parameter direct mode cycle, set the function pins to F[3:0] = 0100, which
as it propagates from the parallel port to the DDS core. Note provides full 12-bit access to the AMP register (amplitude). Be
that high speed modulation requires a DAC reconstruction filter aware, however, this also provides access to the POW register
with sufficient bandwidth to accommodate the instantaneous (phase); therefore, be sure keep the phase bits static. Next, toggle
time domain transitions. the IO_UPDATE pin, which synchronously transfers the new
frequency and phase values from the FTW and POW registers
Because direct access to the DDS parameters occurs via the to the DDS core. This mode of operation reduces the overall
FTW, POW, and AMP registers, the IO_UPDATE pin (see modulation rate by a factor of three because it requires two
Figure 41) adds another layer of flexibility. To accommodate separate operations on the parallel port followed by an
this functionality, the AD9914 provides a register control bit, IO_UPDATE. However, this still allows for modulation
parallel port streaming enable (0x00[17]). sample rates as high as ~49 MSPS.

Rev. F | Page 30 of 45
Data Sheet AD9914

SERIAL PROGRAMMING
To enable SPI operations, set Pin 28 (F0) to logic high and Pin 29 After a write cycle, the programmed data resides in the serial
to Pin 31 (F1 to F3) to logic low. To program the AD9914 with a port buffer and is inactive. I/O_UPDATE transfers data from
parallel interface, see the Parallel Programming section. the serial port buffer to active registers. The input/output
update can be sent either after each communication cycle or
CONTROL INTERFACE—SERIAL INPUT/OUTPUT
when all serial operations are complete. In addition, a change in
The AD9914 serial port is a flexible, synchronous serial commu- profile pins can initiate an input/output update.
nications port allowing easy interface to many industry-standard
microcontrollers and microprocessors. The serial input/output is For a read cycle, Phase 2 is the same as the write cycle with the
compatible with most synchronous transfer formats. following differences: data is read from the active registers, not
the serial port buffer, and data is driven out on the falling edge
The interface allows read/write access to all registers that configure of SCLK.
the AD9914. MSB-first or LSB-first transfer formats are supported.
In addition, the serial interface port can be configured as a single Note that, to read back any profile register (0x0B to 0x1A), the
pin input/output (SDIO) allowing a 2-wire interface, or it can be three external profile pins must be used. For example, if the
configured as two unidirectional pins for input/output (SDIO profile register is Profile 5 (0x15), the PS[0:2] pins must equal
and SDO), enabling a 3-wire interface. Two optional pins 101.This is not required to write to the profile registers.
(I/O_SYNC and CS) enable greater flexibility for designing INSTRUCTION BYTE
systems with the AD9914. The instruction byte contains the following information as
shown in the instruction byte information bit map.
Table 11. Serial Input/Output Pin Description
Pin No. Mnemonic Serial Input/Output Description Instruction Byte Information Bit Map
18 D4/SYNCIO SYNCIO MSB LSB
19 D3/SDO SDO I7 I6 I5 I4 I3 I2 I1 I0
20 D2/SDIO/WR SDIO R/W X A5 A4 A3 A2 A1 A0
21 D1/SCLK/RD SCLK
R/W—Bit 7 of the instruction byte determines whether a read
22 D0/CS/PWD CS—chip select
or write data transfer occurs after the instruction byte write.
Logic 1 indicates a read operation. Logic 0 indicates a write
GENERAL SERIAL INPUT/OUTPUT OPERATION operation.
There are two phases to a serial communications cycle. The first
X—Bit 6 of the instruction byte is don’t care.
is the instruction phase to write the instruction byte into the
AD9914. The instruction byte contains the address of the register A5, A4, A3, A2, A1, A0—Bit 5, Bit 4, Bit 3, Bit 2, Bit 1, and Bit 0
to be accessed and defines whether the upcoming data transfer of the instruction byte determine which register is accessed
is a write or read operation. during the data transfer portion of the communications cycle.

For a write cycle, Phase 2 represents the data transfer between SERIAL INPUT/OUTPUT PORT PIN DESCRIPTIONS
the serial port controller to the serial port buffer. The number SCLK—Serial Clock
of bytes transferred is a function of the register being accessed. The serial clock pin synchronizes data to and from the AD9914
For example, when accessing Control Function Register 2 and to run the internal state machines.
(Address 0x01), Phase 2 requires that four bytes be transferred.
Each bit of data is registered on each corresponding rising edge CS—Chip Select Bar
of SCLK. The serial port controller expects that all bytes of the CS is an active low input that allows more than one device on
register be accessed; otherwise, the serial port controller is put the same serial communications line. The SDO and SDIO pins
out of sequence for the next communication cycle. However, go to a high impedance state when this input is high. If driven
one way to write fewer bytes than required is to use the SYNCIO high during any communications cycle, that cycle is suspended
pin feature. The SYNCIO pin function can abort an input/output until CS is reactivated low. Chip select (CS) can be tied low in
operation and reset the pointer of the serial port controller. systems that maintain control of SCLK.
After a SYNCIO, the next byte is the instruction byte. Note that
SDIO—Serial Data Input/Output
every completed byte written prior to a SYNCIO is preserved in
the serial port buffer. Partial bytes written are not preserved. At Data is always written into the AD9914 on this pin. However,
the completion of any communication cycle, the AD9914 serial this pin can be used as a bidirectional data line. Bit 1 of CFR1
port controller expects the next eight rising SCLK edges to be (0x00) controls the configuration of this pin. The default is
the instruction byte for the next communication cycle. Logic 0, which configures the SDIO pin as bidirectional.

Rev. F | Page 31 of 45
AD9914 Data Sheet
SDO—Serial Data Out SERIAL INPUT/OUTPUT TIMING DIAGRAMS
Data is read from this pin for protocols that use separate lines Figure 42 through Figure 45 provide basic examples of the timing
for transmitting and receiving data. When the AD9914 operates relationships between the various control signals of the serial
in single bidirectional input/output mode, this pin does not input/output port. Most of the bits in the register map are not
output data and is set to a high impedance state. transferred to the internal destinations until assertion of an
SYNCIO—Input/Output Reset input/output update, which is not included in the timing
diagrams that follow.
SYNCIO synchronizes the input/output port state machines
without affecting the contents of the addressable registers. An Note that the SCLK stall condition between the instruction byte
active high input on the SYNCIO pin causes the current cycle and data transfer cycle in Figure 42 to Figure 45 is not
communication cycle to abort. After SYNCIO returns low required.
(Logic 0), another communication cycle can begin, starting MSB/LSB TRANSFERS
with the instruction byte write.
The AD9914 serial port can support both most significant bit
I/O_UPDATE—Input/Output Update (MSB) first or least significant bit (LSB) first data formats. This
The input/output update initiates the transfer of written data functionality is controlled by Bit 0 in CFR1 (0x00). The default
from the serial or parallel input/output port buffer to active format is MSB first. If LSB first is active, all data, including the
registers. I/O_UPDATE is active on the rising edge, and the instruction byte, must follow LSB-first convention. Note that the
pulse width must be greater than one SYNC_CLK period. highest number found in the bit range column for each register is
the MSB, and the lowest number is the LSB for that register.
INSTRUCTION CYCLE DATA TRANSFER CYCLE
CS

SCLK

10836-037
SDIO I7 I6 I5 I4 I3 I2 I1 I0 D7 D6 D5 D4 D3 D2 D1 D0

Figure 42. Serial Port Write Timing, Clock Stall Low

INSTRUCTION CYCLE DATA TRANSFER CYCLE
CS

SCLK

SDIO I7 I6 I5 I4 I3 I2 I1 I0 DON'T CARE

10836-038
SDO DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0

Figure 43. 3-Wire Serial Port Read Timing, Clock Stall Low
INSTRUCTION CYCLE DATA TRANSFER CYCLE
CS

SCLK
10836-039

SDIO I7 I6 I5 I4 I3 I2 I1 I0 D7 D6 D5 D4 D3 D2 D1 D0

Figure 44. Serial Port Write Timing, Clock Stall High

INSTRUCTION CYCLE DATA TRANSFER CYCLE
CS

SCLK
10836-040

SDIO I7 I6 I5 I4 I3 I2 I1 I0 DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0

Figure 45. 2-Wire Serial Port Read Timing, Clock Stall High

Rev. F | Page 32 of 45
Data Sheet AD9914

PARALLEL PROGRAMMING (8-/16-BIT)

The state of the external function pins (F0 to F3) determine the Table 12. Parallel Port Read Timing (See Figure 46)
type of interface used by the AD9914. Pin 28 to Pin 31 are
Parameter Value Unit Test Conditions/Comments
dedicated function pins. To enable the parallel mode interface
tADV 92 ns max Address to data valid time
set Pin 28 to Pin 31 to logic low.
tAHD 0 ns min Address hold time to RD
Parallel programming consists of eight address lines and either signal inactive
eight or 16 bidirectional data lines for read/write operations. tRDLOV 69 ns max RD low to output valid
The logic state on Pin 22 determines the width of the data lines tRDHOZ 50 ns max RD high to data three-state
used. A logic low on Pin 22 sets the data width to eight bits, and tRDLOW 69 ns max RD signal minimum low time
logic high sets the data width to 16 bits. In addition, parallel tRDHIGH 50 ns max RD signal minimum high time
mode has dedicated write/read control inputs. If 16-bit mode is
used, the upper byte, Bits[15:8], goes to the addressed register Table 13. Parallel Port Write Timing (See Figure 47)
and the lower byte, Bits[7:0], goes to the adjacent lower address. Parameter Value Unit Test Conditions/Comments
Parallel input/output operation allows write access to each byte of tASU 1 ns Address setup time to WR signal
any register in a single input/output operation. Readback capability active
for each register is included to ease designing with the AD9914. tDSU 3.8 ns Data setup time to WR signal
active
tAHD 0 ns Address hold time to WR signal
inactive
tDHD 0 ns Data hold time to WR signal
inactive
tWRLOW 2.1 ns WR signal minimum low time
tWRHIGH 3.8 ns WR signal minimum high time
tWR 10.5 ns Minimum write time

A1 A2 A3
A[7:0]

D[7:0] OR D1 D2 D3
D[15:0]
tRDHIGH
tRDLOW

RD

tRDHOZ tRDLOV

10836-041
tAHD tADV

Figure 46. Parallel Port Read Timing Diagram

tWR

A[7:0] A1 A2 A3

D[7:0] OR D1 D2 D3
D[15:0]

WR tASU tAHD
tDSU
10836-042

tWRHIGH tWRLOW tDHD

Figure 47. Parallel Port Write Timing Diagram

Rev. F | Page 33 of 45
AD9914 Data Sheet

REGISTER MAP AND BIT DESCRIPTIONS

Table 14. Register Map
Register Bit Range Default
Name (Serial (Parallel Bit 7 Bit 0 Value
Address) Address) (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 (LSB) (Hex)1
CFR1— [7:0] Digital DAC REF CLK Open External Open SDIO input LSB first 0x08
Control (0x00) power- power- input power-down only mode
Function down down power- control
Register 1 down
(0x00) [15:8] Load LRR Autoclear Autoclear Clear digital Clear phase Open External OSK 0x00
(0x01) at input/ digital phase ramp accumulator OSK enable enable
output ramp accumu- accumulator
update accumu- lator
lator
[23:16] Open Parallel port Enable 0x01
(0x02) streaming sine
enable output
[31:24] Open VCO cal 0x00
(0x03) enable
CFR2— [7:0] Open 0x00
Control (0x04)
Function [15:8] Matched Frequency DRG over Open SYNC_CLK SYNC_CLK Reserved Open 0x09
Register 2 (0x05) latency jump output enable invert
(0x01) enable enable enable
[23:16] Profile Parallel Digital ramp destination Digital ramp Digital Digital Program 0x00
(0x06) mode data port enable ramp no- ramp no- modulus
enable enable dwell high dwell low enable
[31:24] Open 0x00
(0x07)
CFR3— [7:0] Open Manual ICP ICP[2:0] Lock Minimum LDW[1:0] 0x1C
Control (0x08) selection detect
Function enable
Register 3 [15:8] Feedback Divider N[7:0] 0x19
(0x02) (0x09)
[23:16] Open Input Input divider[1:0] Doubler PLL enable PLL input Doubler 0x00
(0x0A) divider enable divider clock edge
reset enable
[31:24] Open 0x00
(0x0B)
CFR4— [7:0] Requires register default value settings (0x20) 0x20
Control (0x0C)
Function [15:8] Requires register default value settings (0x21) 0x21
Register 4 (0x0D)
(0x03)
[23:16] Requires register default value settings (0x05) 0x05
(0x0E)
[31:24] Open Auxiliary DAC CAL DAC CAL 0x00
(0x0F) divider clock enable2
power- power-
down down
Digital Ramp [7:0] Digital ramp lower limit[7:0] 0x00
Lower Limit (0x10)
Register [15:8] Digital ramp lower limit[15:8] 0x00
(0x04) (0x11)
[23:16] Digital ramp lower limit[23:16] 0x00
(0x12)
[31:24] Digital ramp lower limit[31:24] 0x00
(0x13)

Rev. F | Page 34 of 45
Data Sheet AD9914
Register Bit Range Default
Name (Serial (Parallel Bit 7 Bit 0 Value
Address) Address) (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 (LSB) (Hex)1
Digital Ramp [7:0] Digital ramp upper limit[7:0] 0x00
Upper (0x14)
Limit [15:8] Digital ramp upper limit[15:8] 0x00
Register (0x15)
(0x05)
[23:16] Digital ramp upper limit[23:16] 0x00
(0x16)
[31:24] Digital ramp upper limit[31:24] 0x00
(0x17)
Rising Digital [7:0] Rising digital ramp increment step size[7:0] N/A
Ramp Step (0x18)
Size [15:8] Rising digital ramp increment step size[15:8] N/A
Register (0x19)
(0x06)
[23:16] Rising digital ramp increment step size[23:16] N/A
(0x1A)
[31:24] Rising digital ramp increment step size[31:24] N/A
(0x1B)
Falling Digital [7:0] Falling digital ramp decrement step size[7:0] N/A
Ramp Step (0x1C)
Size [15:8] Falling digital ramp decrement step size[15:8] N/A
Register (0x1D)
(0x07)
[23:16] Falling digital ramp decrement step size[23:16] N/A
(0x1E)
[31:24] Falling digital ramp decrement step size[31:24] N/A
(0x1F)
Digital Ramp [7:0] Digital ramp positive slope rate[7:0] N/A
Rate (0x20)
Register [15:8] Digital ramp positive slope rate[15:8] N/A
(0x08) (0x21)
[23:16] Digital ramp negative slope rate[7:0] N/A
(0x22)
[31:24] Digital ramp negative slope rate[15:8] N/A
(0x23)
Lower [7:0] Lower frequency jump point[7:0] 0x00
Frequency (0x24)
Jump [15:8] Lower frequency jump point[15:8] 0x00
Register (0x25)
(0x09)
[23:16] Lower frequency jump point[23:16] 0x00
(0x26)
[31:24] Lower frequency jump point[31:24] 0x00
(0x27)
Upper [7:0] Upper frequency jump point[7:0] 0x00
Frequency (0x28)
Jump [15:8] Upper frequency jump point[15:8] 0x00
Register (0x29)
(0x0A)
[23:16] Upper frequency jump point[23:16] 0x00
(0x2A)
[31:24] Upper frequency jump point[31:24] 0x00
(0x2B)
Profile 0 (P0) [7:0] Frequency Tuning Word 0[7:0] 0x00
Frequency (0x2C)
Tuning [15:8] Frequency Tuning Word 0[15:8] 0x00
Word 0 (0x2D)
Register
[23:16] Frequency Tuning Word 0[23:16] 0x00
(0x0B)
(0x2E)
[31:24] Frequency Tuning Word 0[31:24] 0x00
(0x2F)

Rev. F | Page 35 of 45
AD9914 Data Sheet
Register Bit Range Default
Name (Serial (Parallel Bit 7 Bit 0 Value
Address) Address) (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 (LSB) (Hex)1
Profile 0 (P0) [7:0] Phase Offset Word 0[7:0] 0x00
Phase/ (0x30)
Amplitude [15:8] Phase Offset Word 0[15:8] 0x00
Register (0x31)
(0x0C)
[23:16] Amplitude Scale Factor 0[7:0] 0x00
(0x32)
[31:24] Open Amplitude Scale Factor 0[11:8] 0x00
(0x33)
Profile 1 (P1) [7:0] Frequency Tuning Word 1[7:0] N/A
Frequency (0x34)
Tuning [15:8] Frequency Tuning Word 1[15:8] N/A
Word 1 (0x35)
Register
[23:16] Frequency Tuning Word 1[23:16] N/A
(0x0D)
(0x36)
[31:24] Frequency Tuning Word 1[31:24] N/A
(0x37)
Profile 1 (P1) [7:0] Phase Offset Word 1[7:0] N/A
Phase/ (0x38)
Amplitude [15:8] Phase Offset Word 1[15:8] N/A
Register (0x39)
(0x0E)
[23:16] Amplitude Scale Factor 1[7:0] N/A
(0x3A)
[31:24] Open Amplitude Scale Factor 1[11:8] N/A
(0x3B)
Profile 2 (P2) [7:0] Frequency Tuning Word 2[7:0] N/A
Frequency (0x3C)
Tuning [15:8] Frequency Tuning Word 2[15:8] N/A
Word 2 (0x3D)
Register
[23:16] Frequency Tuning Word 2[23:16] N/A
(0x0F)
(0x3E)
[31:24] Frequency Tuning Word 2[31:24] N/A
(0x3F)
Profile 2 (P2) [7:0] Phase Offset Word 2[7:0] N/A
Phase/ (0x40)
Amplitude [15:8] Phase Offset Word 2[15:8] N/A
Register (0x41)
(0x10)
[23:16] Amplitude Scale Factor 2[7:0] N/A
(0x42)
[31:24] Open Amplitude Scale Factor 2[11:8] N/A
(0x43)
Profile 3 (P3) [7:0] Frequency Tuning Word 3[7:0] N/A
Frequency (0x44)
Tuning [15:8] Frequency Tuning Word 3[15:8] N/A
Word 3 (0x45)
Register
[23:16] Frequency Tuning Word 3[23:16] N/A
(0x11)
(0x46)
[31:24] Frequency Tuning Word 3[31:24] N/A
(0x47)
Profile 3 (P3) [7:0] Phase Offset Word 3[7:0] N/A
Phase/ (0x48)
Amplitude [15:8] Phase Offset Word 3[15:8] N/A
Register (0x49)
(0x12)
[23:16] Amplitude Scale Factor 3[7:0] N/A
(0x4A)
[31:24] Open Amplitude Scale Factor 3[11:8] N/A
(0x4B)

Rev. F | Page 36 of 45
Data Sheet AD9914
Register Bit Range Default
Name (Serial (Parallel Bit 7 Bit 0 Value
Address) Address) (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 (LSB) (Hex)1
Profile 4 (P4) [7:0] Frequency Tuning Word 4[7:0] N/A
Frequency (0x4C)
Tuning [15:8] Frequency Tuning Word 4[15:8] N/A
Word 4 (0x4D)
Register
[23:16] Frequency Tuning Word 4[23:16] N/A
(0x13)
(0x4E)
[31:24] Frequency Tuning Word 4[31:24] N/A
(0x4F)
Profile 4 (P4) [7:0] Phase Offset Word 4[7:0] N/A
Phase/ (0x50)
Amplitude [15:8] Phase Offset Word 4[15:8] N/A
Register (0x51)
(0x14)
[23:16] Amplitude Scale Factor 4[7:0] N/A
(0x52)
[31:24] Open Amplitude Scale Factor 4[11:8] N/A
(0x53)
Profile 5 (P5) [7:0] Frequency Tuning Word 5[7:0] N/A
Frequency (0x54)
Tuning [15:8] Frequency Tuning Word 5[15:8] N/A
Word 5 (0x55)
Register
[23:16] Frequency Tuning Word 5[23:16] N/A
(0x15)
(0x56)
[31:24] Frequency Tuning Word 5[31:24] N/A
(0x57)
Profile 5 (P5) [7:0] Phase Offset Word 5[7:0] N/A
Phase/ (0x58)
Amplitude [15:8] Phase Offset Word 5[15:8] N/A
Register (0x59)
(0x16)
[23:16] Amplitude Scale Factor 5[7:0] N/A
(0x5A)
[31:24] Open Amplitude Scale Factor 5[11:8] N/A
(0x5B)
Profile 6 (P6) [7:0] Frequency Tuning Word 6[7:0] N/A
Frequency (0x5C)
Tuning [15:8] Frequency Tuning Word 6[15:8] N/A
Word 6 (0x5D)
Register
[23:16] Frequency Tuning Word 6[23:16] N/A
(0x17)
(0x5E)
[31:24] Frequency Tuning Word 6[31:24] N/A
(0x5F)
Profile 6 (P6) [7:0] Phase Offset Word 6[7:0] N/A
Phase/ (0x60)
Amplitude [15:8] Phase Offset Word 6[15:8] N/A
Register (0x61)
(0x18)
[23:16] Amplitude Scale Factor 6[7:0] N/A
(0x62)
[31:24] Open Amplitude Scale Factor 6[11:8] n/a
(0x63)
Profile 7 (P7) [7:0] Frequency Tuning Word 7[7:0] N/A
Frequency (0x64)
Tuning [15:8] Frequency Tuning Word 7[15:8] N/A
Word 7 (0x65)
Register
[23:16] Frequency Tuning Word 7[23:16] N/A
(0x19)
(0x66)
[31:24] Frequency Tuning Word 7[31:24] N/A
(0x67)

Rev. F | Page 37 of 45
AD9914 Data Sheet
Register Bit Range Default
Name (Serial (Parallel Bit 7 Bit 0 Value
Address) Address) (MSB) Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 (LSB) (Hex)1
Profile 7 (P7) [7:0] Phase Offset Word 7[7:0] N/A
Phase/ (0x68)
Amplitude [15:8] Phase Offset Word 7[15:8] N/A
Register (0x69)
(0x1A)
[23:16] Amplitude Scale Factor 7[7:0] N/A
(0x6A)
[31:24] Open Amplitude Scale Factor 7[11:8] N/A
(0x6B)
USR0 (0x1B) [7:0] Requires register default value settings (0x00) 0x00
(0x6C)
[15:8] Requires register default value settings (0x08) 0x08
(0x6D)
[23:16] Requires register default value settings (0x00) 0x00
(0x6E)
[31:24] Open PLL lock Read
(0x6F) only

1
A master reset is required after power up. The master reset returns the internal registers to the default values.
2
The DAC CAL enable bit must be manually set and then cleared after each power-up and every time REF CLK or the internal system clock is changed. This initiates an
internal calibration routine to optimize the setup and hold times for internal DAC timing. Failure to calibrate degrades ac performance or makes the device nonfunctional.

Rev. F | Page 38 of 45
Data Sheet AD9914
REGISTER BIT DESCRIPTIONS optional register mnemonic (in parentheses). Also given is the
The serial input/output port registers span an address range of 0 serial address in hexadecimal format and the number of bytes
to 27 (0x00 to 0x1B in hexadecimal notation). This represents a assigned to the register.
total of 28 individual serial registers. If programming in parallel Following each subheading is a table containing the individual
mode, the number of parallel registers increases to 112 individual bit descriptions for that particular register. The location of the
parallel registers. Additionally, the registers are assigned names bit(s) in the register is indicated by a single number or a pair of
according to the functionality. In some cases, a register is given a numbers separated by a colon; that is, a pair of numbers (A:B)
mnemonic descriptor. For example, the register at Serial indicates a range of bits from the most significant (A) to the
Address 0x00 is named Control Function Register 1 and is least significant (B). For example, [5:2] implies Bit Position 5 to
assigned the mnemonic CFR1. Bit Position 2, inclusive, with Bit 0 identifying the LSB of the
This section provides a detailed description of each bit in the register.
AD9914 register map. For cases in which a group of bits serves Unless otherwise stated, programmed bits are not transferred to
a specific function, the entire group is considered a binary word the internal destinations until the assertion of the I/O_UPDATE
and is described in aggregate. pin or a profile pin change.
This section is organized in sequential order of the serial addresses
of the registers. Each subheading includes the register name and
Control Function Register 1 (CFR1)—Address 0x00
Table 15. Bit Description for CFR1
Bits Mnemonic Description
[31:25] Open
24 VCO cal enable 1 = initializes the auto internal PLL calibration. The calibration is required if the PLL is to
provide the internal system clock. Must first be reset to Logic 0 before another calibration
can be issued.
[23:18] Open Open.
17 Parallel port streaming enable 0 = the 32 bit parallel port needs an input/output update to activate or register any FTW,
POW, or AMP data presented to the 32-bit parallel port.
1 = the parallel port continuously samples data on the 32 input pins using SYNC_CLK and
multiplexes the value of FTW/POW/AMP accordingly, per the configuration of the F0 to F3
pins, without the need of an input/output update. Data must meet the setup and hold times
of the SYNC_CLK rising edge. If the function pins are used dynamically to alter data between
parameters, they must also meet the timing of the SYNC_CLK edge.
16 Enable sine output 0 = cosine output of the DDS is selected.
1 = sine output of the DDS is selected (default).
15 Load LRR at input/output update Ineffective unless CFR2[19] = 1.
0 = normal operation of the digital ramp timer (default).
1 = interrupts the digital ramp timer operation to load a new linear ramp rate (LRR) value any
time I/O_UPDATE is asserted or a PS[2:0] change occurs.
14 Autoclear digital ramp accumulator 0 = normal operation of the DRG accumulator (default).
1 = the digital ramp accumulator is reset for one cycle of the DDS clock (SYNC_CLK), after
which the accumulator automatically resumes normal operation. As long as this bit remains
set, the ramp accumulator is momentarily reset each time an input/output update is asserted or a
PS[2:0] change occurs. This bit is synchronized with either an input/output update or a
PS[2:0] change and the next rising edge of SYNC_CLK.
13 Autoclear phase accumulator 0 = normal operation of the DDS phase accumulator (default).
1 = synchronously resets the DDS phase accumulator anytime I/O_UPDATE is asserted or a
profile change occurs.
12 Clear digital ramp accumulator 0 = normal operation of the digital ramp generator (default).
1 = asynchronous, static reset of the DRG accumulator. The ramp accumulator remains reset
as long as this bit remains set. This bit is synchronized with either an input/output update or
a PS[2:0] change and the next rising edge of SYNC_CLK.
11 Clear phase accumulator 0 = normal operation of the DDS phase accumulator (default).
1 = asynchronous, static reset of the DDS phase accumulator as long as this bit is set. This bit
is synchronized with either an input/output update or a PS[2:0] change and the next rising
edge of SYNC_CLK.
10 Open Open.
Rev. F | Page 39 of 45
AD9914 Data Sheet
Bits Mnemonic Description
9 External OSK enable 0 = manual OSK enabled (default).
1 = automatic OSK enabled.
Ineffective unless CFR1[8] = 1.
8 OSK enable 0 = OSK disabled (default).
1 = OSK enabled. To engage any digital amplitude adjust using DRG, profile, or direct mode
via the 32-bit parallel port, or OSK pin, this bit must be set.
7 Digital power-down This bit is effective without the need for an input/output update.
0 = clock signals to the digital core are active (default).
1 = clock signals to the digital core are disabled.
6 DAC power-down 0 = DAC clock signals and bias circuits are active (default).
1 = DAC clock signals and bias circuits are disabled.
5 REFCLK input power-down This bit is effective without the need for an input/output update.
0 = REFCLK input circuits and PLL are active (default).
1 = REFCLK input circuits and PLL are disabled.
4 Open Open.
3 External power-down control 0 = assertion of the EXT_PWR_DWN pin affects power-down.
1 = assertion of the EXT_PWR_DWN pin affects fast recovery power-down.
2 Open Open.
1 SDIO input only 0 = configures the SDIO pin for bidirectional operation; 2-wire serial programming
mode (default).
1 = configures the serial data input/output pin (SDIO) as an input only pin; 3-wire serial
programming mode.
0 LSB first mode 0 = configures the serial input/output port for MSB-first format (default).
1 = configures the serial input/output port for LSB-first format.

Control Function Register 2 (CFR2)—Address 0x01

Table 16. Bit Descriptions for CFR2
Bit(s) Mnemonic Description
[31:24] Open Open.
23 Profile mode enable 0 = disables profile mode functionality (default).
1 = enables profile mode functionality. Profile pins select the desired profile.
22 Parallel data port enable See the Parallel Data Port Modulation Mode section for more details.
0 = disables parallel data port modulation functionality (default).
1 = enables parallel data port modulation functionality.
[21:20] Digital ramp destination See Table 9 for details. Default is 00. See the Digital Ramp Generator (DRG) section for more details.
19 Digital ramp enable 0 = disables digital ramp generator functionality (default).
1 = enables digital ramp generator functionality.
18 Digital ramp no-dwell high See the Digital Ramp Generator (DRG) section for details.
0 = disables no-dwell high functionality (default).
1 = enables no-dwell high functionality.
17 Digital ramp no-dwell low See the Digital Ramp Generator (DRG) section for details.
0 = disables no-dwell low functionality (default).
1 = enables no-dwell low functionality.
16 Programmable modulus enable 0 = disables programmable modulus.
1 = enables programmable modulus.
15 Matched latency enable 0 = simultaneous application of amplitude, phase, and frequency changes to the DDS arrive at
the output in the order listed in Table 2 under data latency (pipe line delay)(default).
1 = simultaneous application of amplitude, phase, and frequency changes to the DDS arrive at
the output simultaneously.
14 Frequency jump enable 0 = disables frequency jump.
1 = enables frequency jump mode. Must have the digital generator DRG enabled for this feature.

Rev. F | Page 40 of 45
Data Sheet AD9914
Bit(s) Mnemonic Description
13 DRG over output enable 0 = disables the DROVER output.
1 = enables the DROVER output.
12 Open Open.
11 SYNC_CLK enable 0 = the SYNC_CLK pin is disabled and forced to a static Logic 0 state; the internal clock signal
continues to operate and provide timing to the data assembler.
1 = the internal SYNC_CLK signal appears at the SYNC_CLK pin (default).
10 SYNC_CLK invert 0 = normal SYNC_CLK polarity; Q data associated with Logic 1, I data with Logic 0 (default).
1 = inverted SYNC_CLK polarity.
9 Reserved Keep logic 0.
[8:0] Open Open.

Control Function Register 3 (CFR3)—Address 0x02

Table 17. Bit Descriptions for CFR3
Bit(s) Mnemonic Description
[31:23] Open Open.
22 Input divider reset 0 = disables input divider reset function.
1 = initiates an input divider reset.
[21:20] Input divider Divides the input REF CLK signal by one of four values (1, 2, 4, 8). Bit 17 must be set to Logic 1
to enable the PLL input divider.
00 = divide by 1.
01 = divide by 2.
10 = divide by 4.
11 = divide by 8.
19 Doubler enable 0 = disables the doubler feature.
1 = enables the doubler feature. Must have the doubler clock edge bit set to Logic 1 to utilize
this feature.
18 PLL enable 0 = disables the internal PLL.
1 = the internal PLL is enabled and the output generates the system clock. The PLL must be
calibrated when enabled via VCO calibration in Register CFR1, Bit 24.
17 PLL input divider enable 0 = disables the PLL input divider function.
1 = enables the PLL input divider function.
16 Doubler clock edge 0 = disables the internal doubler circuit.
1 = enables the doubler circuit. Must have doubler enable bit set to Logic 1 to utilize this
feature.
[15:8] Feedback divider N The N divider value in Bits[15:8] is one part of the total PLL multiplication available. The second
part is the fixed divide by two element in the feedback path. Therefore, the total PLL
multiplication value is 2N. The valid N divider range is 10× to 255×. The default N value for
Bits[15:8] = 25. This sets the total default PLL multiplication to 50× or 2N.
7 Open Open.
6 Manual ICP selection 0 = the internal charge pump current is chosen automatically during the VCO calibration
routine (default).
1 = the internal charge pump is set manually per Table 7.
[5:3] ICP Manual charge pump current selection. See Table 7.
2 Lock detect enable 0 = disables PLL lock detection.
1 = enables PLL lock detection.
[1:0] Minimum LDW Selects the number of REF CLK cycles that the phase error (at the PFD inputs) must remain
within before a PLL lock condition can be read back via Bit 24 in Register 0x00.
00 = 128 REF CLK cycles.
01 = 256 REF CLK cycles.
10 = 512 REF CLK cycles.
11 = 1024 REF CLK cycles.

Rev. F | Page 41 of 45
AD9914 Data Sheet
Control Function Register 4 (CFR4)—Address 0x03
Table 18. Bit Descriptions for DAC
Bit(s) Mnemonic Description
[31:27] Open Open
26 Auxiliary divider 0 = enables the SYNC OUT circuitry.
power-down 1 = disables the SYNC OUT circuitry
25 DAC CAL clock 0 = enables the DAC CAL clock if Bit 26 in Register 0x03 is Logic 0.
power-down 1 = disables the DAC CAL clock.
24 DAC CAL enable 1 = initiates an auto DAC calibration. The DAC CAL calibration is required at power-up and
any time the internal system clock is changed.
[23:0] (See description) These bits must always be programmed with the default values listed in the default column
in Table 14.

Digital Ramp Lower Limit Register—Address 0x04

This register is effective only if the digital ramp enable bit in the CFR2 register (0x01[19]) = 1. See the Digital Ramp Generator (DRG)
section for details.

Table 19. Bit Descriptions for Digital Ramp Lower Limit Register
Bit(s) Mnemonic Description
[31:0] Digital ramp lower limit 32-bit digital ramp lower limit value.

Digital Ramp Upper Limit Register—Address 0x05

This register is effective only if the digital ramp enable bit in the CFR2 register (0x01[19]) = 1. See the Digital Ramp Generator (DRG)
section for details.

Table 20. Bit Descriptions for Digital Ramp Limit Register

Bit(s) Mnemonic Description
[31:0] Digital ramp upper limit 32-bit digital ramp upper limit value.

Rising Digital Ramp Step Size Register—Address 0x06

This register is effective only if the digital ramp enable bit in the CFR2 register (0x01[19]) = 1. See the Digital Ramp Generator (DRG)
section for details.

Table 21. Bit Descriptions for Rising Digital Ramp Step Size Register
Bit(s) Mnemonic Description
[31:0] Rising digital ramp 32-bit digital ramp increment step size value.
increment step size

Falling Digital Ramp Step Size Register—Address 0x07

This register is effective only if the digital ramp enable bit in the CFR2 register (0x01[19]) = 1. See the Digital Ramp Generator (DRG)
section for details.

Table 22. Bit Descriptions for Falling Digital Ramp Step Size Register
Bit(s) Mnemonic Description
[31:0] Falling digital ramp 32-bit digital ramp decrement step size value.
decrement step size

Rev. F | Page 42 of 45
Data Sheet AD9914
Digital Ramp Rate Register—Address 0x08
This register is effective only if the digital ramp enable bit in the CFR2 register (0x01[19]) = 1. See the Digital Ramp Generator (DRG)
section for details.

Table 23. Bit Descriptions for Digital Ramp Rate Register

Bit(s) Mnemonic Description
[31:16] Digital ramp negative slope rate 16-bit digital ramp negative slope value that defines the time interval between decrement values.
[15:0] Digital ramp positive slope rate 16-bit digital ramp positive slope value that defines the time interval between increment values.

Lower Frequency Jump Register—Address 0x09

This register is effective only if the digital ramp enable bit (0x01[19]) = 1 and the frequency jump enable bit (0x01[14]) = 1 in the CFR2
register. See the Digital Ramp Generator (DRG) section for details.

Table 24. Bit Descriptions for Lower Frequency Jump Register

Bit(s) Mnemonic Description
[31:0] Lower frequency jump 32-bit digital lower frequency jump value. Any time the lower frequency jump value is
point reached during a frequency sweep, the output frequency jumps to the upper frequency
value instantaneously and continues frequency sweeping in a phase-continuous manner.

Upper Frequency Jump Register—Address 0x0A

This register is effective only if the digital ramp enable bit (0x01[19]) = 1 and the frequency jump enable bit (0x01[14]) = 1 in the CFR2
register. See the Digital Ramp Generator (DRG) section for details.

Table 25. Bit Descriptions for Upper Frequency Jump Register

Bit(s) Mnemonic Description
[31:0] Upper frequency jump 32-bit digital upper frequency jump value. Any time the upper frequency jump value is
point reached during a frequency sweep, the output frequency jumps to the lower frequency
value instantaneously and continues frequency sweeping in a phase-continuous manner.

Rev. F | Page 43 of 45
AD9914 Data Sheet
Profile Registers
There are 16 serial input/output addresses (Address 0x0B to To enable profile mode, set the profile mode enable bit in CFR2
Address 0x01A) dedicated to device profiles. Eight of the 16 (0x01[23]) = 1. The active profile register is selected using the
profiles house up to eight single tone frequencies. The remaining external PS[2:0] pins.
eight profiles contain the corresponding phase offset and
amplitude parameters relative to the profile pin setting.

Profile 0 to Profile 7, Single Tone Registers—0x0B, 0x0D, 0x0F, 0x11, 0x13, 0x15, 0x17, 0x19
Four bytes are assigned to each register.

Table 26. Bit Descriptions for Profile 0 to Profile 7 Single Tone Registers
Bit(s) Mnemonic Description
[31:0] Frequency tuning word This 32-bit number controls the DDS frequency.

Profile 0 to Profile 7, Phase Offset and Amplitude Registers—0x0C, 0x0E, 0x10, 0x12, 0x14, 0x16, 0x18, 0x1A
Four bytes are assigned to each register.

Table 27. Bit Descriptions for Profile 0 to Profile 7 Phase Offset and Amplitude Registers
Bit(s) Mnemonic Description
[31:28] Open Open.
[27:16] Amplitude scale factor This 12-bit word controls the DDS frequency. Note that the OSK enable bit (0x00[8]) must be set to logic
high to make amplitude adjustments.
[15:0] Phase offset word This 16-bit word controls the DDS frequency.

USR0 Register—Address 0x1B

Table 28. Bit Descriptions for USR0 Register
Bit(s) Mnemonic Description
[31:25] Open
24 PLL lock This is a readback bit only. If Logic 1 is read back, the PLL is locked. Logic 0 represents a nonlocked state.
[23:0] (See description) These bits must always be programmed with the default values listed in the default column in Table 14.

Rev. F | Page 44 of 45
Data Sheet AD9914

OUTLINE DIMENSIONS
12.10 0.30
12.00 SQ 0.60 MAX 0.23
11.90 0.60 0.18
MAX
PIN 1
67 88 INDICATOR
66 1
PIN 1
INDICATOR

11.85 0.50
11.75 SQ BSC 6.80
EXPOSED
11.65 PAD 6.70 SQ
6.60

0.50
0.40 45 22
44 23
0.30
TOP VIEW BOTTOM VIEW

0.70 10.50
0.65 REF
*0.90 12° MAX
0.60 0.045 FOR PROPER CONNECTION OF
0.85 THE EXPOSED PAD, REFER TO
0.75 0.025 THE PIN CONFIGURATION AND
0.005 FUNCTION DESCRIPTIONS
SEATING COPLANARITY SECTION OF THIS DATA SHEET.
PLANE 0.08
0.138~0.194 REF

07-03-2014-C
PKG-004081

*COMPLIANT TO JEDEC STANDARDS MO-220-VRRD

EXCEPT FOR MINIMUM THICKNESS AND LEAD COUNT.

Figure 48. 88-Lead Lead Frame Chip Scale Package [LFCSP_VQ]

12 mm × 12 mm Body, Very Thin Quad
(CP-88-5)
Dimensions shown in millimeters

ORDERING GUIDE
Parameter1 Temperature Range Package Description Package Option
AD9914BCPZ −40°C to +85°C 88-Lead Lead Frame Chip Scale Package [LFCSP_VQ] CP-88-5
AD9914BCPZ-REEL7 −40°C to +85°C 88-Lead Lead Frame Chip Scale Package [LFCSP_VQ] CP-88-5
AD9914/PCBZ Evaluation Board
1
Z = RoHS Compliant Part.

©2012–2016 Analog Devices, Inc. All rights reserved. Trademarks and

registered trademarks are the property of their respective owners.
D10836-0-6/16(F)

Rev. F | Page 45 of 45