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LMH 6522

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24 views35 pages

LMH 6522

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LMH6522

www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

LMH6522 High Performance Quad DVGA


Check for Samples: LMH6522

1FEATURES Each channel of LMH6522 has an independent,


digitally controlled attenuator and a high linearity,

23 OIP3: 49dBm @ 200MHz differential output, amplifier. All circuitry has been
• Noise Figure: 8.5dB optimized for low distortion and maximum system
• Voltage Gain: 26dB design flexibility. Power consumption is managed by
a three-state enable pin. Individual channels can be
• 1dB Gain Steps
disabled or placed into a Low Power Mode or a
• −3dB Bandwidth of 1400 MHz higher performance, High Power Mode.
• Gain Step Accuracy: 0.2 dB The LMH6522 digitally controlled attenuator provides
• Disable Function for Each Channel precise 1dB gain steps over a 31dB range. The digital
• Parallel and Serial Gain Control attenuator can be controlled by either a SPI™ Serial
bus or a high speed parallel bus.
• Low Power Mode for Power Management
Flexibility The output amplifier has a differential output, allowing
• Small Footprint WQFN Package large signal swings on a single 5V supply. The low
impedance output provides maximum flexibility when
driving a wide range filter designs or analog to digital
APPLICATIONS converters. For applications which have very large
• Cellular Base Stations changes in signal level LMH6522 can support up to
• Wideband and Narrowband IF Sampling 62dB of gain range by cascading channels.
Receivers The LMH6522 operates over the industrial
• Wideband Direct Conversion temperature range of −40°C to +85°C. The LMH6522
is available in a 54-Pin, thermally enhanced, WQFN
• ADC Driver
package.
DESCRIPTION Performance Curve
The LMH6522 contains four, high performance,
digitally controlled variable gain amplifiers (DVGA). It 60 35

has been designed for use in narrowband and 50 30


broadband IF sampling applications. Typically, the

POWER GAIN (dB)


LMH6522 drives a high performance ADC in a broad 40 25
OIP3 (dBm)

range of mixed signal and digital communication


applications such as mobile radio and cellular base 30 20
stations where automatic gain control (AGC) is
20 f = 200 MHz 15
required to increase system dynamic range.
10 VOUT= 2VPPD 10
@ filter input
0 5
50 100 150 200 250 300
FILTER INPUT RESISTANCE ( )

Figure 1. OIP3 vs Filter Input Resistance

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2 SPI is a trademark of Motorola, Inc..
3 All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Copyright © 2011–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
LMH6522
SNOSB53D – JULY 2011 – REVISED MARCH 2013 www.ti.com

Block Diagram
+5V

Attenuator
INA+ OUTA+
26 dB
INA- OUTA-
0 dB to 31 dB

Attenuator
INB+ OUTB+
26 dB
INB- OUTB-
0 dB to 31 dB

5
ATTEN_A 5
ATTEN_B

EN_A
Digital EN_B
4 Control,
SPI
(Serial MODE
5 or
ATTEN_D 5
Parallel) ATTEN_C

EN_D
EN_C

Attenuator
INC+ OUTC+
26 dB
INC- OUTC-
0 dB to 31 dB

Attenuator
IND+ OUTD+
26 dB
IND- OUTD-
0 dB to 31 dB

GND

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.

2 Submit Documentation Feedback Copyright © 2011–2013, Texas Instruments Incorporated

Product Folder Links: LMH6522


LMH6522
www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

Absolute Maximum Ratings (1) (2)


(3)
ESD Tolerance
Human Body Model 2 kV
Machine Model 200V
Charged Device Model 750V
Positive Supply Voltage (Pin 3) −0.6V to 5.5V
Differential Voltage between Any Two Grounds <200 mV
Analog Input Voltage Range −0.6V to 5.5V
Digital Input Voltage Range −0.6V to 5.5V
Output Short Circuit Duration
(one pin to ground) Infinite
Junction Temperature +150°C
Storage Temperature Range −65°C to +150°C
Soldering Information
Infrared or Convection (30 sec) 260°C

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for
which the device is intended to be functional, but specific performance is not ensured. For ensured specifications, see the Electrical
Characteristics tables.
(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications.
(3) Human Body Model, applicable std. MIL-STD-883, Method 3015.7. Machine Model, applicable std. JESD22-A115-A (ESD MM std. of
JEDEC)Field-Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC).

Operating Ratings (1)


Supply Voltage (Pin 3) 4.75V to 5.25V
Differential Voltage Between Any Two Grounds <10 mV
Analog Input Voltage Range,
AC Coupled 0V to V+
(2)
Temperature Range −40°C to +85°C

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for
which the device is intended to be functional, but specific performance is not ensured. For ensured specifications, see the Electrical
Characteristics tables.
(2) The maximum power dissipation is a function of TJ(MAX), θJA. The maximum allowable power dissipation at any ambient temperature is
PD = (TJ(MAX) – TA)/ θJA. All numbers apply for packages soldered directly onto a PC Board.

(1)
Package Thermal Resistance (θJA) (θJC)
54pin WQFN 23°C/W 4.7°C/W

(1) Junction to ambient (θJA) thermal resistance measured on JEDEC 4 layer board. Junction to case (θJC) thermal resistance measured at
exposed thermal pad; package is not mounted to any PCB.

Copyright © 2011–2013, Texas Instruments Incorporated Submit Documentation Feedback 3


Product Folder Links: LMH6522
LMH6522
SNOSB53D – JULY 2011 – REVISED MARCH 2013 www.ti.com

5V Electrical Characteristics (1) (2) (3)


The following specifications apply for single supply with V+ = 5V, Maximum Gain (0 Attenuation), RL = 200Ω, VOUT = 4VPPD,
fin = 200 MHz, High Power Mode, Boldface limits apply at temperature extremes.
Min Typ Max
Symbol Parameter Conditions (4) (5) (4) Units

Dynamic Performance
3dBBW −3dB Bandwidth VOUT= 2 VPPD 1.4 GHz
Output Noise Voltage Source = 100Ω 30 nV/√Hz
NF Noise Figure Source = 100Ω 8.5 dB
OIP3 Output Third Order Intercept Point f = 100 MHz, VOUT = 4 dBm per tone 53 dBm
Output Third Order Intercept Point f = 200 MHz, VOUT = 4 dBm per tone 49
OIP2 Output Second Order Intercept Point POUT= 4 dBm per Tone, f1 =101 MHz, 78 dBm
f2=203 MHz
IMD3 Third Order Intermodulation f = 100 MHz, VOUT = 4 dBm per tone −98 dBc
Products
Third Order Intermodulation f = 200 MHz, VOUT = 4 dBm per tone −90
Products
P1dB 1dB Compression Point 17 dBm
HD2 Second Order Harmonic Distortion f = 100 MHz, VOUT =2 VPPD −88 dBc
HD2 Second Order Harmonic Distortion f = 200 MHz, VOUT =2 VPPD −78 dBc
HD3 Third Order Harmonic Distortion f = 100 MHz, VOUT =2 VPPD −99 dBc
HD3 Third Order Harmonic Distortion f = 200 MHz, VOUT =2 VPPD −75 dBc
CMRR Common Mode Rejection Pin = −15 dBm −35 dBc
Analog I/O
RIN Input Resistance Differential, Measured at DC 97 Ω
VICM Input Common Mode Voltage Self Biased 2.5 V
Maximum Input Voltage Swing Volts peak to peak, differential 5.5 VPPD
Maximum DIfferential Output Differential, f < 10MHz 10 VPPD
Voltage Swing
ROUT Output Resistance Differential, Measured at DC 20 Ω
XTLK Channel to Channel Crosstalk Maximum Gain, f=200MHz −65 dBc
Gain Parameters
Maximum Voltage Gain Attenuation code 00000 25.74 dB
Minimum Gain Attenuation code 11111 −4.3 dB
Gain Steps 32
Gain Step Size 1.0 dB
Channel Matching Gain error between channels ±0.15 dB
Gain Step Error Any two adjacent steps over entire range ±0.5 dB
Gain Step Error Any two adjacent steps, 0 dB attenuation ±0.1 dB
to 23 dB attenuation
Gain Step Phase Shift Any two adjacent steps over entire range ±3 Degrees
Gain Step Phase Shift Any two adjacent steps, 0dB attenuation ±2
Degrees
to 23 dB attenuation
Gain Step Switching Time 20 ns
Enable/ Disable Time Settled to 90% level 200 ns

(1) Electrical Table values apply only for factory testing conditions at the temperature indicated. No specification of parametric performance
is indicated in the electrical tables under conditions different than those tested
(2) Negative input current implies current flowing out of the device.
(3) Drift determined by dividing the change in parameter at temperature extremes by the total temperature change.
(4) Limits are 100% production tested at 25°C. Limits over the operating temperature range are specified through correlation using
Statistical Quality Control (SQC) methods.
(5) Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary
over time and will also depend on the application and configuration. The typical values are not tested and are not ensured on shipped
production material.
4 Submit Documentation Feedback Copyright © 2011–2013, Texas Instruments Incorporated

Product Folder Links: LMH6522


LMH6522
www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

5V Electrical Characteristics(1)(2)(3) (continued)


The following specifications apply for single supply with V+ = 5V, Maximum Gain (0 Attenuation), RL = 200Ω, VOUT = 4VPPD,
fin = 200 MHz, High Power Mode, Boldface limits apply at temperature extremes.
Min Typ Max
Symbol Parameter Conditions (4) (5) (4) Units

Power Requirements
ICC Supply Current 465 485 mA
P Power 2.3 2.43 W
IBIAS Output Pin Bias Current External inductor, no load, VOUT< 200 mV 36 mA
ICC Disabled Supply Current 74 mA
All Digital Inputs Except Enables
Logic Compatibility TTL, 2.5V CMOS, 3.3V CMOS, 5V CMOS
VIL Logic Input Low Voltage 0 0.4 V
VIH Logic Input High Voltage 2.0 5.0 V
IIH Logic Input High Input Current Digital Input Voltage = 2.0V −9 μA
IIL Logic Input Low Input Current Digital Input Voltage = 0.4V −47 μA
Enable Pins
VIL Logic Input Low Voltage Amplifier disabled 0 0.4 V
VIM Logic Input Mid Level Amplifier Low Power Mode 0.6 1.9 V
VIH Logic Input High Level Amplifier High Power Mode 2.2 5 V
VSB Enable Pin Self Bias Voltage No external load 1.37 V
IIL Input Bias Current, Logic Low Digital input voltage = 0.2V −200 µA
IIM Input Bias Current, Logic Mid Digital input voltage = 1.5V 28 µA
IIH Input Bias Current, Logic High Digital input voltage = 3.0V 500 µA
Parallel Mode Timing
tGS Setup Time 3 ns
tGH Hold Time 3 ns
Serial Mode
fCLK SPI Clock Frequency 50% duty cycle, ATE tested @ 20MHz 20 50 MHz
Low Power Mode
(Enable pins are self biased)
ICC Total Supply Current all four channels in low power mode 370 398 mA
IBIAS Output Pin Bias Current External Inductor, No Load, VOUT< 200mV 26 mA
ICC Disabled Supply Current Enable Pin < 0.4V 74 mA
OIP3 Output Intermodulation Intercept f = 200 MHz, V OUT = 4 dBm per tone 44 dBm
Point
P1dB 1dB Compression Point 16 dBm
HD2 Second Order Harmonic Distortion f = 100 MHz, VOUT =2 VPPD −90 dBc
HD2 Second Order Harmonic Distortion f = 200 MHz,VOUT = 2 VPPD −79 dBc
HD3 Third Order Harmonic Distortion f = 100 MHz, VOUT = 2 VPPD −91 dBc
HD3 Third Order Harmonic Distortion f = 200 MHz, VOUT = 2 VPPD −79 dBc

Copyright © 2011–2013, Texas Instruments Incorporated Submit Documentation Feedback 5


Product Folder Links: LMH6522
LMH6522
SNOSB53D – JULY 2011 – REVISED MARCH 2013 www.ti.com

CONNECTION DIAGRAM

A1/CLK

A2/CSb

A3/SDI
B0

B1

B2

B3

B4

A0
50

49

48

47

46
54

53

52

51
GND 1 45 A4/SDO
INA+ 2 44 OUTA+
INA- 3 43 OUTA-
GND 4 42 +5VA
MODE 5 41 ENBA
GND 6 40 +5VB
INB+ 7 39 OUTB+
Top View
INB- 8 38 OUTB-
10 mm x 5.5 mm x 0.8 mm
GND 9 37 ENBB
0.5 mm pitch
GND 10 36 ENBC
INC+ 11 35 OUTC+
INC- 12 34 OUTC-
GND 13 33 +5VC
GND 14 32 ENBD
GND 15 31 +5VD
IND+ 16 30 OUTD+
GND
IND- 17 29 OUTD-
GND 18 28 D4
23

24

25

26

27
19

20

21

22
C0

C1

C2

C3

C4

D0

D1

D2

D3

Figure 2. 54-Pin WQFN


Top View

PIN DESCRIPTIONS
Pin Number Symbol Pin Category Description
Analog I/O
2, 3 INA+, INA - Analog Input Differential inputs channel A
44, 43 OUTA+, OUTA- Analog Output Differential outputs Channel A
7, 8 INB+, INB - Analog Input Differential inputs channel B
39, 38 OUTB+, OUTB- Analog Output Differential outputs Channel B
11, 12 INC+, INC - Analog Input Differential inputs channel C
35, 34 OUTC+, OUTC- Analog Output Differential outputs Channel C
16, 17 IND+, IND - Analog Input Differential inputs channel D
30, 29 OUTD+, OUTD- Analog Output Differential outputs Channel D
Power
1, 4, 6, 9, 10, 13, 14, GND Ground Ground pins. Connect to low impedance ground
15, 18 plane. All pin voltages are specified with respect to
the voltage on these pins. The exposed thermal pad
is internally bonded to the ground pins.
31, 33, 40, 42 +5VD, +5VC, +5VB, Power Power supply pins. Valid power supply range is
+5VA 4.75V to 5.25V.
Exposed Center Pad Thermal/ Ground Thermal management/ Ground
Digital Inputs
5 MODE Digital Input 0= Parallel Mode, 1 = Serial Mode
Parallel Mode Digital Pins, MODE = Logic Low
49, 48, 47, 46, 45 A0, A1, A2, A3, A4 Digital Input Channel A attenuator control
41 ENBA Digital Input Channel A enable pin
54, 53, 52, 51, 50 B0, B1, B2, B3, B4 Digital Input Channel B attenuator control

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Product Folder Links: LMH6522


LMH6522
www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

PIN DESCRIPTIONS (continued)


Pin Number Symbol Pin Category Description
37 ENBB Digital Input Channel B enable pin: pin has three states: Low,
Mid, High
19, 20, 21, 22, 23 C0, C1, C2, C3, C4 Digital Input Channel C attenuator control
36 ENBC Digital Input Channel C enable pin
24, 25, 26, 27, 28 D0, D1, D2, D3, D4 Digital Input Channel D attenuator control
32 ENBD Digital Input Channel D enable pin
Serial Mode Digital Pins, MODE = Logic High
SPI™ Compatible
45 SDO Digital Output- Open Collector Serial Data Output (Requires external bias.)
46 SDI Digital Input Serial Data In
47 CSb Digital Input Chip Select
48 CLK Digital Input Clock

PIN LIST
Pin Description Pin Description
1 GND 28 D4
2 INA+ 29 OUTD−
3 INA− 30 OUTD+
4 GND 31 +5VD
5 MODE 32 ENBD
6 GND 33 +5VC
7 INB+ 34 OUTC−
8 INB− 35 OUTC+
9 GND 36 ENBC
10 GND 37 ENBB
11 INC+ 38 OUTB−
12 INC− 39 OUTB+
13 GND 40 +5VB
14 GND 41 ENBA
15 GND 42 +5VA
16 IND+ 43 OUTA−
17 IND− 44 OUTA+
18 GND 45 A4 / SDO
19 C0 46 A3 / SDI
20 C1 47 A2 / CSb
21 C2 48 A1 / CLK
22 C3 49 A0
23 C4 50 B4
24 D0 51 B3
25 D1 52 B2
26 D2 53 B1
27 D3 54 BO

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Product Folder Links: LMH6522
LMH6522
SNOSB53D – JULY 2011 – REVISED MARCH 2013 www.ti.com

Typical Performance Characteristics


(TA = 25°C, V+ = 5V, RL = 200Ω, Maximum Gain, High Power, f= 200MHz; LMH6522 soldered onto LMH6522EVAL
evaluation board, Unless Specified).
Frequency Response, 2dB Steps OIP3 vs Attenuation
30 52
POUT= 4dBm / Tone
25
48
20

OIP3 (dBm)
15 44
GAIN (dB)

10
40 High Power Mode
5 Low Power Mode

0 36
-5
32
-10
1 10 100 1000 10000 0 4 8 12 16 20 24 28 32
ATTENUATION (dB)
FREQUENCY (MHz)
Figure 3. Figure 4.

OIP3 vs Output Power OIP3 vs Load Resistance


52 55
High Power Mode
Low Power Mode
48
50

44
OIP3 (dBm)

OIP3 (dBm)

45
40
40
36

35
32
VOUT= 4VPPD
28 30
0 2 4 6 8 10 12 0 100 200 300 400 500 600
OUTPUT POWER, EACH TONE (dBm) LOAD RESISTANCE ( )
Figure 5. Figure 6.

OIP3 vs Frequency OIP3 vs Supply Voltage


56 52

POUT=4dBm / Tone
52
48
48
OIP3 (dBm)

OIP3 (dBm)

44 44

40
40
36
High Power Mode High Power Mode
Low Power Mode Low Power Mode
32 36
100 200 300 400 500 4.50 4.75 5.00 5.25 5.50
FREQUENCY (MHz) SUPPLY VOLTAGE (V)
Figure 7. Figure 8.

8 Submit Documentation Feedback Copyright © 2011–2013, Texas Instruments Incorporated

Product Folder Links: LMH6522


LMH6522
www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

Typical Performance Characteristics (continued)


(TA = 25°C, V+ = 5V, RL = 200Ω, Maximum Gain, High Power, f= 200MHz; LMH6522 soldered onto LMH6522EVAL
evaluation board, Unless Specified).
OIP3 vs Temperature Supply Current vs Supply Voltage
56 550
High Power Mode
Low Power Mode

SUPPLY CURRENT (mA)


500
52
OIP3 (dBm)

450
48
400

44
350
High Power Mode
Low Power Mode
40 300
-45 -30 -15 0 15 30 45 60 75 90 4.50 4.75 5.00 5.25 5.50
TEMPERATURE (Degrees C) SUPPLY VOLTAGE (V)
Figure 9. Figure 10.

Supply Current vs Temperature Maximum Gain vs Temperature


500 28.0
High Power Mode High Power Mode
Low Power Mode Low Power Mode
27.5
475
SUPPLY CURRENT (mA)

MAXIMUM GAIN (dB) 27.0


450
26.5

425 26.0

25.5
400
25.0
375
24.5

350 24.0
-45 -30 -15 0 15 30 45 60 75 90 -45 -30 -15 0 15 30 45 60 75 90
TEMPERATURE (Degrees C) TEMPERATURE (Degrees C)
Figure 11. Figure 12.

HD2 vs Frequency, High Power Mode HD3 vs Frequency, High Power Mode
-20 -20
Ch A Ch A
Ch B POUT=10dBm Ch B POUT=10dBm
-30 Ch C -30 Ch C
Ch D Ch D
-40
-40
HD3 (dBc)

-50
HD2 (dB)

-50
-60
-60
-70
-70
-80
-80 -90

-90 -100
0 100 200 300 400 500 0 100 200 300 400 500
FREQUENCY (MHz) FREQUENCY (MHz)
Figure 13. Figure 14.

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Product Folder Links: LMH6522
LMH6522
SNOSB53D – JULY 2011 – REVISED MARCH 2013 www.ti.com

Typical Performance Characteristics (continued)


(TA = 25°C, V+ = 5V, RL = 200Ω, Maximum Gain, High Power, f= 200MHz; LMH6522 soldered onto LMH6522EVAL
evaluation board, Unless Specified).
HD2 vs Frequency, Low Power Mode HD3 vs Frequency, Low Power Mode
-30 -20
Ch A Ch A
Ch B POUT= 10dBm Ch B POUT=10dBm
-40 Ch C -30 Ch C
Ch D Ch D
-50 -40

HD3 (dBc)
HD2 (dBc)

-60 -50

-70 -60

-80 -70

-90 -80

-100 -90
0 100 200 300 400 500 0 100 200 300 400 500
FREQUENCY (MHz) FREQUENCY (MHz)
Figure 15. Figure 16.

HD2 vs Attenuation HD3 vs Attenuation


-40 -40
High Power Mode High Power Mode
Low Power Mode Low Power Mode
-50 HD3 (dBc) -50
HD2 (dBc)

-60 -60

POUT= 4dBm POUT= 4dBm


-70 -70

-80 -80

-90 -90
0 4 8 12 16 20 24 28 32 0 4 8 12 16 20 24 28 32
ATTENUATION (dB) ATTENUATION (dB)
Figure 17. Figure 18.

HD2 vs Output Power HD3 vs Output Power


-20 -20
High Power Mode High Power Mode
Low Power Mode Low Power Mode
-30 -30

-40 -40
HD2 (dBc)

HD3 (dBc)

-50 -50

-60 -60

-70 -70

-80 -80

-90 -90

-100 -100
-4 0 4 8 12 16 20 -4 0 4 8 12 16 20
OUTPUT POWER (dBm) OUTPUT POWER (dBm)
Figure 19. Figure 20.

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Product Folder Links: LMH6522


LMH6522
www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

Typical Performance Characteristics (continued)


(TA = 25°C, V+ = 5V, RL = 200Ω, Maximum Gain, High Power, f= 200MHz; LMH6522 soldered onto LMH6522EVAL
evaluation board, Unless Specified).
Isolation, Adjacent Channels Isolation, Non-Adjacent Channels
-20 -40
IN A OUT B IN A OUT C
IN B OUT A IN A OUT D
-30 IN B OUT C -50 IN B OUT D
IN C OUT B IN C OUT A
IN C OUT D IN D OUT A
-40 -60
ISOLATION (dBc)

ISOLATION (dBc)
IN D OUT C IN D OUT B

-50 -70

-60 -80

-70 -90

-80 -100

-90 -110
10 100 1000 10 100 1000
FREQUENCY (MHz) FREQUENCY (MHz)
Figure 21. Figure 22.

Channel Matching
Channel Matching, Maximum Gain Attenuation Code 10000
4 4
A to B A to B
A to C A to C
A to D 3 A to D
3
GAIN MATCHING (dB)
GAIN MATCHING (dB)

2 2

1 1

0 0

-1 -1

-2 -2
10 100 1000 10 100 1000
FREQUENCY (MHz) FREQUENCY (MHz)
Figure 23. Figure 24.

Gain Step Amplitude Error Gain Step Phase Error


1.0 4
50 MHz
200 MHz
0.8 300 MHz 2
PHASE ERROR (Degrees)
AMPLITUDE ERROR (dB)

0.6
0
0.4

0.2 -2

0.0
-4
-0.2
-6 50 MHz
-0.4 200 MHz
300 MHz
-0.6 -8
1 6 11 16 21 26 31 1 6 11 16 21 26 31
ATTENUATION (dB) ATTENUATION (dB)
Figure 25. Figure 26.

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LMH6522
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Typical Performance Characteristics (continued)


(TA = 25°C, V+ = 5V, RL = 200Ω, Maximum Gain, High Power, f= 200MHz; LMH6522 soldered onto LMH6522EVAL
evaluation board, Unless Specified).
Cumulative Amplitude Error Cumulative Phase Error
2.0 4
50 MHz
200 MHz 2
1.5 300 MHz

PHASE ERROR (Degrees)


AMPLITUDE ERROR (dB)

0
-2
1.0
-4
50 MHz
0.5 -6 200 MHz
-8 300 MHz
0.0
-10
-12
-0.5
-14
-1.0 -16
1 6 11 16 21 26 31 1 6 11 16 21 26 31
ATTENUATION (dB) ATTENUATION (dB)
Figure 27. Figure 28.

Noise Figure vs Attenuation Noise Figure vs Frequency


40 14

36 13
32
NOISE FIGURE (dB)
NOISE FIGURE (dB)

12
28
11
24
10
20
9
16

12 8

8 7
0 4 8 12 16 20 24 28 32 0 100 200 300 400
ATTENUATION (dB) FREQUENCY (MHz)
Figure 29. Figure 30.

Enable Timing, High Power Enable Timing, Low Power


3 5 3 3
Output Output
Enable Pin Enable Pin

2 4 2 2
ENA PIN (V)
ENA PIN (V)

VOUT(V)

1 1
VOUT(V)

1 3

0 2 0 0

-1 1 -1 -1

-2 0 -2 -2
0 100 200 300 400 500 600 700 800 0 100 200 300 400 500 600 700 800
TIME (ns) TIME (ns)
Figure 31. Figure 32.

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Product Folder Links: LMH6522


LMH6522
www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

Typical Performance Characteristics (continued)


(TA = 25°C, V+ = 5V, RL = 200Ω, Maximum Gain, High Power, f= 200MHz; LMH6522 soldered onto LMH6522EVAL
evaluation board, Unless Specified).
Gain Step Timing, 16dB Step Gain Step Timing, 8dB Step
3 5 3 5
Output Output
A4 Pin A3 Pin
2 4 2 4

A4 PIN (V)

A3 PIN (V)
VOUT(V)

VOUT(V)
1 3 1 3

0 2 0 2

-1 1 -1 1

-2 0 -2 0
0 10 20 30 40 50 60 70 80 0 10 20 30 40 50 60 70 80
TIME (ns) TIME (ns)
Figure 33. Figure 34.

Gain Step Timing, 4dB Step Gain Step Timing, 2dB Step
3 5 3 5
Output Output
A2 Pin A1 Pin
2 4 2 4
A2 PIN (V)

A1 PIN (V)
VOUT(V)

VOUT(V)

1 3 1 3

0 2 0 2

-1 1 -1 1

-2 0 -2 0
0 10 20 30 40 50 60 70 80 0 10 20 30 40 50 60 70 80
TIME (ns) TIME (ns)
Figure 35. Figure 36.

Gain Step Timing, 1dB Step CMRR vs Frequency


3 5 -10
Output Maximum Gain
A0 Pin 16dB Attenuation
-20
2 4
-30
CMRR (dBc)
A0 PIN (V)
VOUT(V)

1 3
-40

-50
0 2

-60
-1 1
-70

-2 0 -80
0 10 20 30 40 50 60 70 80 1 10 100 1000
TIME (ns) FREQUENCY (MHz)
Figure 37. Figure 38.

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Typical Performance Characteristics (continued)


(TA = 25°C, V+ = 5V, RL = 200Ω, Maximum Gain, High Power, f= 200MHz; LMH6522 soldered onto LMH6522EVAL
evaluation board, Unless Specified).
Input Impedance Output Impedance
300 150
R R
jX Z = R + jX jX Z = R +jX
250 |Z| 125 |Z|

OUTPUT IMPEDANCE ( )
INPUT IMPEDANCE ( )

200 100

150 75

100 50

50 25

0 0

-50 -25

-100 -50
0 100 200 300 400 500 0 100 200 300 400 500
FREQUENCY (MHz) FREQUENCY (MHz)
Figure 39. Figure 40.

Power Sweep, High Power Mode Power Sweep, Low Power Mode
20 20
100 MHz 100 MHz
200 MHz 200 MHz
300 MHz 16 300 MHz
16
OUTPUT POWER (dBm)
OUTPUT POWER (dBm)

12 12

8 8

4 4

0 0

-4 -4
-30 -25 -20 -15 -10 -5 0 -30 -25 -20 -15 -10 -5 0
INPUT POWER (dBm) INPUT POWER (dBm)
Figure 41. Figure 42.

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APPLICATION INFORMATION

VCC
100: 100:
FILTER 1 PH FILTER
0.01 PF 40.2: 0.01 PF

RF 100: ¼ LMH6522 ADC

0.01 PF 40.2: 0.01 PF 100:


1 PH
LO
5
GAIN 0-4
ENABLE

Figure 43. LMH6522 Typical Application

INTRODUCTION
The LMH6522 is a fully differential amplifier optimized for signal path applications up to 400 MHz. The LMH6522
has a 100Ω input and a low impedance output. The gain is digitally controlled over a 31 dB range from +26dB to
−5dB. The LMH6522 is optimized for accurate gain steps and minimal phase shift combined with low distortion
products. This makes the LMH6522 ideal for voltage amplification and an ideal analog to digital converter (ADC)
driver where high linearity is necessary.
+5V

Attenuator
INA+ OUTA+
26 dB
INA- OUTA-
0 dB to 31 dB

Attenuator
INB+ OUTB+
26 dB
INB- OUTB-
0 dB to 31 dB

5
ATTEN_A 5
ATTEN_B

EN_A
Digital EN_B
4 Control,
SPI
(Serial MODE
5 or
ATTEN_D 5
Parallel) ATTEN_C

EN_D
EN_C

Attenuator
INC+ OUTC+
26 dB
INC- OUTC-
0 dB to 31 dB

Attenuator
IND+ OUTD+
26 dB
IND- OUTD-
0 dB to 31 dB

GND

Figure 44. LMH6522 Block Diagram

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BASIC CONNECTIONS
A voltage between 4.75 V and 5.25 V should be applied to the supply pin labeled +5V. Each supply pin should
be decoupled with a low inductance, surface-mount ceramic capacitor of 0.01uF as close to the device as
possible. Additional bypass capacitors of 0.1uF and 1nF are optional, but would provide bypassing over a wider
frequency range.
The outputs of the LMH6522 need to be biased to ground using inductors and output coupling capacitors of
0.01uF are recommended. The input pins are self biased to 2.5V and should be ac-coupled with 0.01uF
capacitors as well. The output bias inductors and ac-coupling capacitors are the main limitations for operating at
low frequencies. Larger values of inductance on the bias inductors and larger values of capacitance on the
coupling capacitors will give more low frequency range. Using bias inductors over 1 uH, however, may
compromise high frequency response due to unwanted parasitic loading on the amplifier output pins.
Each channel of the LMH6522 consists of a digital step attenuator followed by a low distortion 26 dB fixed gain
amplifier and a low impedance output stage. The attenuation is digitally controlled over a 31 dB range from 0dB
to 31dB. The LMH6522 has a 100Ω differential input impedance and a low, 20Ω, output impedance.
Each channel of the LMH6522 has an enable pin. Grounding the enable pin will put the channel in a power
saving shutdown mode. Additionally, there are two “on” states which gives the option of two power modes. High
Power Mode is selected by biasing the enable pins at 2.0 V or higher. The LMH6522 enable pins will self bias to
the Low Power State, alternatively supplying a voltage between 0.6V and 1.8V will place the channel in Low
Power Mode. If connected to a TRI-STATE buffer the LMH6522 enable pins will be in shutdown for a logic 0
output, in High Power Mode for a logic 1 state and they will self bias to Low Power Mode for the high impedance
state.
+5V

+
0.01 PF
SOURCE
LOAD

50: 0.01 PF OUT+ 40.2: 0.01 PF


IN+

AC
¼
100:
LMH6522
OUT-
50: 0.01 PF IN -
40.2: 0.01 PF

5 1 PH 1 PH

A0 ± A4

Figure 45. LMH6522 Basic Connections Schematic

INPUT CHARACTERISTICS
The LMH6522 input impedance is set by internal resistors to a nominal 100Ω. Process variations will result in a
range of values. At higher frequencies parasitic reactances will start to impact the impedance. This characteristic
will also depend on board layout and should be verified on the customer’s system board.
At maximum gain the digital attenuator is set to 0 dB and the input signal will be much smaller than the output. At
minimum gain the output is 5 dB or more smaller than the input. In this configuration the input signal will begin to
clip against the ESD protection diodes before the output reaches maximum swing limits. The input signal cannot
swing more than 0.5V below the negative supply voltage (normally 0V) nor should it exceed the positive supply
voltage. The input signal will clip and cause severe distortion if it is too large. Because the input stage self biases
to approximately mid rail the supply voltage will impose the limit for input voltage swing.
At higher frequencies the LMH6522 input impedance is not purely resistive. In Figure 46 a circuit is shown that
matches the amplifier input impedance with a source that is 100Ω. This would be the case when connecting the
LMH6522 directly to a mixer. For an easy way to calculate the L and C circuit values there are several options for
online tools or down-loadable programs. The following tool might be helpful.

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Excel can also be used for simple circuits; however, the “Analysis ToolPak” add-in must be installed to calculate
complex numbers.
http://www.circuitsage.com/matching/matcher2.html
SOURCE IMPEDANCE = 100:
f = 200 MHz
ZAMP = (130 + j10):
ZIN = (97.8-j1.5):
5V

L1
LMH6522
ZIN

ZAMP
C1

L2

L1, L2 = 22 nH
5
C1 = 4 pF
GAIN 0-4

Figure 46. Differential LC Conversion Circuit

OUTPUT CHARACTERISTICS
The LMH6522 has a low impedance output very similar to a traditional Op-amp output. This means that a wide
range of loads can be driven with good performance. Matching load impedance for proper termination of filters is
as easy as inserting the proper value of resistor between the filter and the amplifier. This flexibility makes system
design and gain calculations very easy.
By using a differential output stage the LMH6522 can achieve very large voltage swings on a single 5V supply.
This is illustrated in Figure 47. This figure shows how a voltage swing of 5VPPD is realized while only swinging 2.5
VPP on each output. The LMH6522 can swing up to 10 VPPD which is sufficient to drive most ADCs to full scale
while using a matched impedance anti alias filter between the amplifier and the ADC. The LMH6522 has been
designed for AC coupled applications and has been optimized for operation above 5 MHz.
2.5
(OUT+) - (OUT-)
2.0
1.5
1.0
0.5 OUT+
VOUT (V)

1.25 VP
0.0
-0.5 OUT-
-1.0
2.5 VPP
-1.5
-2.0
5 VPPD (DIFFERENTIAL)
-2.5
0 45 90 135 180 225 270 315 360

PHASE (Degrees)

Figure 47. Differential Output Voltage

Like most closed loop amplifiers the LMH6522 output stage can be sensitive to capacitive loading. To help with
board layout and to help minimize sensitivity to bias inductor capacitance the LMH5522 output lines have internal
10Ω resistors. These resistors should be taken into account when choosing matching resistor values. This is
shown in Figure 45 as using 40.2 Ω resistors instead of 50 Ω resistors to match the 100 Ω differential load. Best
practise is to place the external termination resistors as close to the DVGA output pins as possible. Due to
reactive components between the DVGA output and the filter input it may be desirable to use even smaller value
resistors than a simple calculation would indicate. For instance, at 200 MHz resistors of 30 Ohms provide slightly
better OIP3 performance on the LMH6522EVAL evaluation board and may also provide a better match to the
filter input.

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The LMH6522 output pins require a DC path to ground. On the evaluation board, inductors are installed to
provide proper output biasing. The bias current is approximately 36mA per output pin. The resistance of the
output bias inductors will raise the output common mode slightly. An inductor with low resistance will keep the
output bias voltage close to zero, so the DC resistance of the inductor chosen will be important. It is also
important to make sure that the inductor can handle the 36mA of bias current.
In addition to the DC current in the inductor there will be some AC current as well. With large inductors and high
operating frequencies the inductor will present a very high impedance and will have minimal AC current. If the
inductor is chosen to have a smaller value, or if the operating frequency is very low there could be enough AC
current flowing in the inductor to become significant. The total current should not exceed the inductor current
rating.
Another reason to choose low resistance bias inductors is that due to the nature of the LMH6522 output stage,
the output offset voltage is determined by the output bias components. The output stage has an offset current
that is typically 3mA and this offset current, multiplied by the resistance of the output bias inductors will
determine the output offset voltage.
The ability of the LMH6522 to drive low impedance loads while maintaining excellent OIP3 performance creates
an opportunity to greatly increase power gain and drive low impedance filters. Figure 48 shows the OIP3
performance of the LMH6522 over a range of filter impedances. Also on the same graph is the power gain
realized by changing load impedance. The power gain reflects the 6dB of loss caused by the termination
resistors necessary to match the amplifier output impedance to the filter characteristic impedance. The graphs
shows the ability of the LMH6522 to drive a constant voltage to an ADC input through various filter impedances
with very little change in OIP3 performance. This gives the system designer much needed flexibility in filter
design.
55 40
OIP3 High Power Mode
50 35

POWER GAIN (dB)


OIP3 Low Power Mode
45 30
OIP3 (dBm)

40 25

35 Power Gain @ Load 20

30 15
VOUT= 4VPPD
f = 200 MHz
25 10
50 100 150 200 250 300
FILTER INPUT RESISTANCE ( )

Figure 48. OIP3 and Power Gain vs Filter Impedance


OIP3 and Gain Measured at Amplifier Output, Filter Back Terminated

Printed circuit board (PCB) design is critical to high frequency performance. In order to ensure output stability the
load matching resistors should be placed as close to the amplifier output pins as possible. This allows the
matching resistors to mask the board parasitics from the amplifier output circuit. An example of this is shown in
Figure 49. If the FIilter is a bandpass filter with no DC path the 0.01µF coupling capacitors can be eliminated.
The LMH6522EVAL evaluation board is available to serve a guide for system board layout.

1P
FILTER
0.01P
RT
+ +IN
RT
¼ LMH6522 VRM ADC16DV160
RT RT
- . -IN
0.01P
1P

Figure 49. Output Configuration


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CASCADE OPERATION

VCC VCC
1 PH 1 PH
0.01 PF 0.01 PF 40.2: 0.01 PF

VIN 100: ¼ LMH6522 100: ¼ LMH6522 VOUT

0.01 PF 0.01 PF 40.2: 0.01 PF


1 PH 1 PH

Figure 50. Schematic for Cascaded Amplifiers

With four amplifiers in one package the LMH6522 is ideally configured for cascaded operation. By using two
amplifiers in series additional gain range can be achieved. The schematic in Figure 50 shows one way to
connect two stages of the LMH6522. The resultant frequency response is shown below in Figure 51. When using
the LMH6522 amplifiers in a cascade configuration it is important to keep the signal level within reasonable limits
at all nodes of the signal path. With over 40dB of total gain it is possible to amplify signals to clipping levels if the
gain is not set correctly.
50

40
GAIN @ LOAD (dB)

30

20

10

-10

-20
1 10 100 1000
FREQUENCY (MHz)

Figure 51. Frequency Response of Cascaded Amplifiers

DIGITAL CONTROL
The LMH6522 will support two modes of control, parallel mode and serial mode (SPI compatible). Parallel mode
is fastest and requires the most board space for logic line routing. Serial mode is compatible with existing SPI
compatible systems.
The LMH6522 has gain settings covering a range of 31 dB. To avoid undesirable signal transients the LMH6522
should not be powered on with large inputs signals present. Careful planning of system power on sequencing is
especially important to avoid damage to ADC inputs.
The LMH6522 was designed to interface with 2.5V to 5V CMOS logic circuits. If operation with 5V logic is
required care should be taken to avoid signal transients exceeding the DVGA supply voltage. Long, unterminated
digital signal traces are particularly susceptible to these transients. Signal voltages on the logic pins that exceed
the device power supply voltage may trigger ESD protection circuits and cause unreliable operation.
Some pins on the LMH6522 have different functions depending on the digital control mode. These functions will
be described in the sections to follow.

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Table 1. Pins with Dual Functions (1)


Pin MODE = 0 MODE = 1
45 A4 SDO*
46 A3 SDI
47 A2 CSb
48 A1 CLK

(1) Pin 45 requires external bias. See Serial Mode Section for Details.

PARALLEL INTERFACE
Parallel mode offers the fastest gain update capability with the drawback of requiring the most board space
dedicated to control lines. When designing a system that requires very fast gain changes parallel mode is the
best selection. To place the LMH6522 into parallel mode the MODE pin (pin 5) is set to the logical zero state.
Alternately the MODE pin can be connected directly to ground.
The attenuator control pins are internally biased to logic high state with weak pull up resistors. The MODE pin
has a weak internal resistor to ground. The enable pins bias to a mid logic state which is the Low Power Mode.
The LMH6522 has a 5-bit gain control bus. Data from the gain control pins is immediately sent to the gain circuit
(i.e. gain is changed immediately). To minimize gain change glitches all gain pins should change at the same
time. In order to achieve the very fast gain step switching time the internal gain change circuit is very fast. Gain
glitches could result from timing skew between the gain set bits. This is especially the case when a small gain
change requires a change in state of three or more gain control pins. If necessary the DVGA could be put into a
disabled state while the gain pins are reconfigured and then brought active when they have settled.
ENA , ENB, ENC and END pins are provided to reduce power consumption by disabling the highest power
portions of the LMH6522. The gain register will preserve the last active gain setting during the disabled state.
These pins have three logic states and will float to the middle or low power, enabled state if left floating. When
grounded the EN pins will disable the associated channel and when biased to the highest logic level the
associated channel will be in the high power, enabled state. See the Typical Performance Characteristics section
for disable and enable timing information.
CONTROL LOGIC LMH6522

4
pd en[a:d]*
5
ga[4:0] ga[4:0]
5
gb[4:0] gb[4:0]
5
gc[4:0] gc[4:0]
5
gd[4:0] gd[4:0]

*Enable pins are tri state buffer compatible.

Figure 52. Parallel Mode Connection

SPI™ COMPATIBLE SERIAL INTERFACE


Serial interface allows a great deal of flexibility in gain programming and reduced board complexity. Using only 4
wires for both channels allows for significant board space savings. The trade off for this reduced board
complexity is slower response time in gain state changes. For systems where gain is changed only infrequently
or where only slow gain changes are required serial mode is the best choice. To place the LMH6522 into serial
mode the MODE pin (Pin 5) should be put into the logic high state. Alternatively the MODE pin an be connected
directly to the 5V supply bus.
The LMH6522 serial interface is a generic 4-wire synchronous interface that is compatible with SPI type
interfaces that are used on many microcontrollers and DSP controllers. In this configuration the pins function as
shown in the pin description table. The SPI interface uses the following signals: clock input (CLK), serial data in
(SDI), serial data out (SDO), and serial chip select (CSb). The chip select pin is active low.
The enable pins are inactive in the serial mode. These pins can be left disconnected for serial mode.

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The CLK pin is the serial clock pin. It is used to register the input data that is presented on the SDI pin on the
rising edge; and to source the output data on the SDO pin on the falling edge. User may disable clock and hold it
in the low state, as long as the clock pulse-width minimum specification is not violated when the clock is enabled
or disabled.
The CSb pin is the chip select pin. The b indicates that this pin is actually a “NOT chip select” since the chip is
selected in the logic low state. Each assertion starts a new register access - i.e., the SDATA field protocol is
required. The user is required to deassert this signal after the 16th clock. If the CSb pin is deasserted before the
16th clock, no address or data write will occur. The rising edge captures the address just shifted-in and, in the
case of a write operation, writes the addressed register. There is a minimum pulse-width requirement for the
deasserted pulse - which is specified in the Electrical Specifications section.
The SDI pin is the input pin for the serial data. It must observe setup / hold requirements with respect to the
SCLK. Each cycle is 16-bits long
The SDO pin is the data output pin. This output is normally at a high impedance state, and is driven only when
CSb is asserted. Upon CSb assertion, contents of the register addressed during the first byte are shifted out with
the second 8 SCLK falling edges. Upon power-up, the default register address is 00h. The SDO pin requires
external bias for clock speeds over 1MHz. See Figure 54 for details on sizing the external bias resistor. Because
the SDO pin is a high impedance pin, the board capacitance present at the pin will restrict data out speed that
can be achieved. For a RC limited circuit the frequency is ~ 1/ (2*Pi*RC). As shown in the figure resistor values
of 300 to 2000 Ohms are recommended.
Each serial interface access cycle is exactly 16 bits long as shown in Figure 53. Each signal's function is
described below. the read timing is shown in Figure 55, while the write timing is shown in Figure 56.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

SCLK

CSb

COMMAND FIELD DATA FIELD

C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0
(MSB) (LSB)

SDI R/Wb 0 0 0 A3 A2 A1 A0 Write DATA

Reserved (3-bits) Address (4-bits)

D7 D6 D5 D4 D3 D2 D1 D0
(MSB) (LSB)
Hi-Z
SDO Read DATA

Data (8-bits)

Single Access Cycle

Figure 53. Serial Interface Protocol (SPI compatible)

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Control Logic LMH6522


Clock out CLK
Chip Select out CSb
Data Out SDI
Data In
SDO
R
20:
V+ (Logic High)

For SDO (MISO) pin only:


VOH = V+, 12 mA
Max
VOL = (V+) - {0.012 * (R+20) + Vcesat}
Vcesat ~= 0.2V

Recommended:
R = 300 Ohms to 2000 Ohms
V+ (Logic) = 2.5V to 5V

Figure 54. Internal Operation of the SDO pin

R/Wb Read / Write bit. A value of 1 indicates a read operation, while a


value of 0 indicates a write operation.
Reserved Not used. Must be set to 0.
ADDR: Address of register to be read or written.
DATA In a write operation the value of this field will be written to the
addressed register when the chip select pin is deasserted. In a read
operation this field is ignored.

st th th
1 clock 8 clock 16 clock

SCLK

tCSH tCSS tCSH tCSS

CSb

tOZD tODZ
tOD

SDO D7 D1 D0

Figure 55. Read Timing

Table 2. Read Timing


Data Output on SDO Pin
Parameter Description
tCSH Chip select hold time
tCSS Chip select setup time
tOZD Initial output data delay
tODZ High impedance delay
tOD Output data delay

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tPL tPH
16th clock

SCLK

tSU tH

SDI Valid Data Valid Data

Figure 56. Write Timing


Data Written to SDI Pin

Table 3. Write Timing


Data Input on SDI Pin
Parameter Description
tPL Minimum clock low time (clock duty dycle)
tPH Minimum clock high time (clock duty cycle)
tSU Input data setup time
tH Input data hold time

Table 4. Serial Word Format for LMH6522


C7 C6 C5 C4 C3 C2 C1 C0
1= read 0 0 0 0 000= CHA
0=write 001=CHB
010=CHC
011=CHD
100=Fast Adjust

Table 5. CH A through D Register Definition


7 6 5 4 3 2 1 0
Reserved, =0 Power Level: Enable: 0 = Attenuation Setting: 00000 = Maximum Gain
0= Low OFF 11111 = Minimum Gain
1=High 1= ON

Table 6. Fast Adjust Register Definition


7 6 5 4 3 2 1 0
CH D CH C CH B CH A

Table 7. Fast Adjust Codes


Code Action
00 No Change
01 Decrease Attenuation by 1 Step (1dB)
10 Increase Attenuation by 1 Step (1dB)
11 Reserved, action undefined

SPISU2 SPI CONTROL BOARD AND TINYI2CSPI SOFTWARE


Also available separately from the LMH6522EVAL evaluation board is a USB to SPI control board and supporting
software. The SPISU2 board will connect directly to the LMH6522 evaluation board and provides a simple way to
test and evaluate the SPI interface. For more details refer to the LMH6522EVAL user's guide. The evaluation
board user's guide provides instructions on connecting the SPISU2 board and for configuring the TinyI2CSPI
software.

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THERMAL MANAGEMENT
The LMH6522 is packaged in a thermally enhanced package. The exposed pad is connected to the GND pins. It
is recommended, but not necessary, that the exposed pad be connected to the supply ground plane. In any
case, the thermal dissipation of the device is largely dependent on the attachment of this pad to the system
printed circuit board (PCB). The exposed pad should be attached to as much copper on the PCB as possible,
preferably external copper. However, it is also very important to maintain good high speed layout practices when
designing a system board. Please refer to the LMH6522 evaluation board for suggested layout techniques.
The LMH6522EVAL evaluation board was designed for both signal integrity and thermal dissipation. The
LMH6522EVAL has eight layers of copper. The inner copper layers are two ounce copper and are as solid as
design constraints allow. The exterior copper layers are one ounce copper in order to allow fine geometry
etching. The benefit of this board design is significant. The JEDEC standard 4 layer test board gives a θJA of
23°C/W. The LMH6522EVAL eight layer board gives a measured θJA of 15°C/W (ambient temperature 25°C, no
forced air). With the typical power dissipation of 2.3W this is a temperature difference of 18 degrees in junction
temperature between the standard 4 layer board and the enhanced 8 layer evaluation board. In a system design
the location and power dissipation of other heat sources may change the results observed compared with the
LMH6522EVAL board.
Applying a heat sink to the package will also help to remove heat from the device. The ATS-54150K-C2–R0 heat
sink, manufactured by Advanced Thermal Solutions, provided good results in lab testing. Using both a heat sink
and a good board thermal design will provide the best cooling results. If a heat sink will not fit in the system
design, the external case can be used as a heat sink.
Package information is available on the TI web site.
http://www.ti.com/packaging

INTERFACING TO AN ADC
The LMH6522 was designed to be used with high speed ADCs such as the ADC16DV160. As shown in the
Typical Application on page 1, AC coupling provides the best flexibility especially for IF sub-sampling
applications.
The inputs of the LMH6522 will self bias to the optimum voltage for normal operation. The internal bias voltage
for the inputs is approximately mid rail which is 2.5V with the typical 5V power supply condition. In most
applications the LMH6522 input will need to be AC coupled.
The output pins require a DC path to ground that will carry the ~36 mA of bias current required to power the
output transistors. The output common mode voltage should be established very near to ground. This means that
using RF chokes or RF inductors is the easiest way to bias the LMH6522 output pins. Inductor values of 1μH to
400nH are recommended. High Q inductors will provide the best performance. If low frequency operation is
desired, particular care must be given to the inductor selection because inductors that offer good performance at
very low frequencies often have very low self resonant frequencies. If very broadband operation is desired the
use of conical inductors such as the BCL–802JL from Coilcraft may be considered. These inductors offer very
broadband response, at the expense of large physical size and a high DC resistance of 3.4 Ohms.

ADC Noise Filter


Below are schematics and a table of values for second order Butterworth response filters for some common IF
frequencies. These filters, shown in Figure 57, offer a good compromise between bandwidth, noise rejection and
cost. This filter topology is the same as is used on the ADC14V155KDRB High IF Receiver reference design
board. This filter topology works best with the 12, 14 and 16 bit analog to digital converters shown in Table 8.

Table 8. Filter Component Values


Center Frequency 75 MHz 150 MHz 180 MHz 250 MHz
Bandwidth 40 MHz 60 MHz 75 MHz 100 MHz
R1, R2 90Ω 90Ω 90Ω 90Ω
L1, L2 390 nH 370 nH 300 nH 225 nH
C1, C2 10 pF 3 pF 2.7 pF 1.9 pF
C3 22 pF 19 pF 15 pF 11 pF
L5 220 nH 62 nH 54 nH 36 nH

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Table 8. Filter Component Values (continued)


R3, R4 100Ω 100Ω 100Ω 100Ω

R1 C1
L1 L5
AMP VOUT -
ADC VIN +

R3

ADC ZIN
C3
C2

R4
L2
ADC VIN -
AMP VOUT +
R2

ADC VCM

Figure 57. Sample Filter

POWER SUPPLIES
The LMH6522 was designed primarily to be operated on 5V power supplies. The voltage range for V+ is 4.75V to
5.25V. Power supply accuracy of 2.5% or better is advised. When operated on a board with high speed digital
signals it is important to provide isolation between digital signal noise and the LMH6522 inputs. The
SP16160CH1RB reference board provides an example of good board layout.

DYNAMIC POWER MANAGEMENT, USING LOW POWER MODE


The LMH6522 offers the option of a reduced power mode of operation referred to as Low Power Mode. In this
mode of operation power consumption is reduced by approximately 20%. In many applications the linearity of the
LMH6522 is fully adequate for most signal conditions. This would apply for a radio in a noise limited environment
with no close-in blocker signals. During these conditions the LMH6522 can be operated in the low power mode.
When a blocking signal is detected, or when system dynamic range needs to be increased, the LMH6522 can be
rapidly switched from the Low Power Mode to the standard, High Power Mode.
The output response shown in Figure 58 is for a 2 MHz switching frequency pulse applied to the enable pin with
a 50 MHz input signal. Analysis with a spectrum analyzer showed that the power mode switching spurs created
by the switching signal were −80dBc with respect to the 50 MHz tone signal. This shows that rapid switching of
power modes has virtually no impact on the signal quality.
2 5

Enable
1 VOUT 4
ENABLE (V)
VOUT(V)

0 3

-1 2

-2 High Power Mode Low Power Mode 1

-3 0
0.0 0.1 0.2 0.3 0.4 0.5
TIME ( S)

Figure 58. Signal Output During Mode Change


from High Power Mode to Low Power Mode

Copyright © 2011–2013, Texas Instruments Incorporated Submit Documentation Feedback 25


Product Folder Links: LMH6522
LMH6522
SNOSB53D – JULY 2011 – REVISED MARCH 2013 www.ti.com

COMPATIBLE HIGH SPEED ANALOG TO DIGITAL CONVERTERS

Product Number Max Sampling Rate (MSPS) Resolution Channels


ADC12L063 62 12 SINGLE
ADC12DL065 65 12 DUAL
ADC12L066 66 12 SINGLE
ADC12DL066 66 12 DUAL
CLC5957 70 12 SINGLE
ADC12L080 80 12 SINGLE
ADC12DL080 80 12 DUAL
ADC12C080 80 12 SINGLE
ADC12C105 105 12 SINGLE
ADC12C170 170 12 SINGLE
ADC12V170 170 12 SINGLE
ADC14C080 80 14 SINGLE
ADC14C105 105 14 SINGLE
ADC14DS105 105 14 DUAL
ADC14155 155 14 SINGLE
ADC14V155 155 14 SINGLE
ADC16V130 130 16 SINGLE
ADC16DV160 160 16 DUAL
ADC08D500 500 8 DUAL
ADC08500 500 8 SINGLE
ADC08D1000 1000 8 DUAL
ADC081000 1000 8 SINGLE
ADC08D1500 1500 8 DUAL
ADC081500 1500 8 SINGLE
ADC08(B)3000 3000 8 SINGLE
ADC08L060 60 8 SINGLE
ADC08060 60 8 SINGLE
ADC10DL065 65 10 DUAL
ADC10065 65 10 SINGLE
ADC10080 80 10 SINGLE
ADC08100 100 8 SINGLE
ADCS9888 170 8 SINGLE
ADC08(B)200 200 8 SINGLE
ADC11C125 125 11 SINGLE
ADC11C170 170 11 SINGLE

26 Submit Documentation Feedback Copyright © 2011–2013, Texas Instruments Incorporated

Product Folder Links: LMH6522


LMH6522
www.ti.com SNOSB53D – JULY 2011 – REVISED MARCH 2013

REVISION HISTORY

Changes from Revision C (March 2013) to Revision D Page

• Changed layout of National Data Sheet to TI format .......................................................................................................... 25

Copyright © 2011–2013, Texas Instruments Incorporated Submit Documentation Feedback 27


Product Folder Links: LMH6522
PACKAGE OPTION ADDENDUM

www.ti.com 10-Dec-2020

PACKAGING INFORMATION

Orderable Device Status Package Type Package Pins Package Eco Plan Lead finish/ MSL Peak Temp Op Temp (°C) Device Marking Samples
(1) Drawing Qty (2) Ball material (3) (4/5)
(6)

LMH6522SQ/NOPB ACTIVE WQFN NJY 54 2000 RoHS & Green SN Level-2-260C-1 YEAR -40 to 85 L6522

LMH6522SQE/NOPB ACTIVE WQFN NJY 54 250 RoHS & Green SN Level-2-260C-1 YEAR -40 to 85 L6522

(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.

(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.

(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.

(6)
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Addendum-Page 1
PACKAGE OPTION ADDENDUM

www.ti.com 10-Dec-2020

Addendum-Page 2
PACKAGE MATERIALS INFORMATION

www.ti.com 30-May-2024

TAPE AND REEL INFORMATION

REEL DIMENSIONS TAPE DIMENSIONS


K0 P1

B0 W
Reel
Diameter
Cavity A0
A0 Dimension designed to accommodate the component width
B0 Dimension designed to accommodate the component length
K0 Dimension designed to accommodate the component thickness
W Overall width of the carrier tape
P1 Pitch between successive cavity centers

Reel Width (W1)


QUADRANT ASSIGNMENTS FOR PIN 1 ORIENTATION IN TAPE

Sprocket Holes

Q1 Q2 Q1 Q2

Q3 Q4 Q3 Q4 User Direction of Feed

Pocket Quadrants

*All dimensions are nominal


Device Package Package Pins SPQ Reel Reel A0 B0 K0 P1 W Pin1
Type Drawing Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant
(mm) W1 (mm)
LMH6522SQ/NOPB WQFN NJY 54 2000 330.0 16.4 5.8 10.3 1.0 12.0 16.0 Q1
LMH6522SQE/NOPB WQFN NJY 54 250 178.0 16.4 5.8 10.3 1.0 12.0 16.0 Q1

Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION

www.ti.com 30-May-2024

TAPE AND REEL BOX DIMENSIONS

Width (mm)
H
W

*All dimensions are nominal


Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
LMH6522SQ/NOPB WQFN NJY 54 2000 356.0 356.0 36.0
LMH6522SQE/NOPB WQFN NJY 54 250 208.0 191.0 35.0

Pack Materials-Page 2
PACKAGE OUTLINE

NJY0054A SCALE 2.000


WQFN
WQFN

5.6
B A
5.4

PIN 1 INDEX AREA 0.5


0.3
0.3
10.1 0.2
9.9

DETAIL
OPTIONAL TERMINAL
TYPICAL

0.8 MAX
C

SEATING PLANE

2X 4
3.51±0.1 (0.1)
SEE TERMINAL 19 27
DETAIL
18 28

50X 0.5

7.5±0.1
2X
8.5

1 45
54 46 0.3
54X
PIN 1 ID 0.2
0.5
(OPTIONAL) 54X 0.1 C A B
0.3
0.05 C
4214993/A 07/2013

NOTES:

1. All linear dimensions are in millimeters. Dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M.
2. This drawing is subject to change without notice.
3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance.

www.ti.com
EXAMPLE BOARD LAYOUT

NJY0054A WQFN
WQFN

(3.51)
SYMM
54X (0.6) SEE DETAILS
54 46
54X (0.25)
1
45

50X (0.5)

SYMM (7.5)
(9.8)
(1.17)
TYP

2X
(1.16)

18 28

( 0.2) TYP
VIA 19 27

(1) TYP

(5.3)

LAND PATTERN EXAMPLE


SCALE:8X

0.07 MAX 0.07 MIN


ALL AROUND ALL AROUND

METAL SOLDER MASK


OPENING

SOLDER MASK METAL


OPENING

NON SOLDER MASK


SOLDER MASK
DEFINED
DEFINED
(PREFERRED)

SOLDER MASK DETAILS


4214993/A 07/2013

NOTES: (continued)

4. This package is designed to be soldered to a thermal pad on the board. For more information, refer to QFN/SON PCB application note
in literature No. SLUA271 (www.ti.com/lit/slua271).

www.ti.com
EXAMPLE STENCIL DESIGN

NJY0054A WQFN
WQFN

SYMM
METAL
TYP
(0.855) TYP
54X (0.6) 54 46
54X (0.25)
1
45

50X (0.5)
(1.17)
TYP

SYMM
(9.8)

12X (0.97)

18 28

19 27
12X (1.51)

(5.3)

SOLDERPASTE EXAMPLE
BASED ON 0.125mm THICK STENCIL

EXPOSED PAD
67% PRINTED SOLDER COVERAGE BY AREA
SCALE:10X

4214993/A 07/2013

NOTES: (continued)

5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate
design recommendations.

www.ti.com
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