LTC5549

2GHz to 14GHz Microwave

Mixer with Integrated
LO Frequency Doubler
Features Description
nn Upconversion or Downconversion The LTC®5549 is a general purpose passive double-
nn High IIP3: +28.2dBm at 5.8GHz balanced mixer that can be used for upconversion or
+22.8dBm at 12GHz downconversion. The RF port is designed for the 2GHz to
nn 8.0dB Conversion Loss at 5.8GHz 14GHz band and the IF port is optimized for 500MHz to
nn +14.3dBm Input P1dB at 5.8GHz 6GHz operation. An integrated LO buffer amplifier supports
nn Integrated LO Buffer: 0dBm LO Drive LO frequencies from 1GHz to 12GHz, requiring only 0dBm
nn Bypassable Integrated LO Frequency Doubler LO power. The LTC5549 delivers high IIP3 and input P1dB
nn Low LO-RF Leakage: <–30dBm with low power consumption.
nn 50Ω Single-Ended RF, LO and IF Ports
An internal LO frequency doubler can be enabled by a
nn 3.3V/115mA Supply
CMOS-compatible digital control pin, allowing operation
nn Fast Turn ON/OFF for TDD Operation
with a lower, one-half LO input frequency. This allows the
nn 2mm × 3mm, 12-Lead QFN Package mixer’s LO port to be used with existing synthesizers, such
as the LTC6946 and LTC6948 family.
Applications The LTC5549’s high level of integration minimizes the total
solution cost, board space and system level variation with
nn Microwave Transceivers its 2mm × 3mm package size.
nn Wireless Backhaul
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
nn Point-to-Point Microwave Technology Corporation. All other trademarks are the property of their respective owners.
nn Phased-Array Antennas
nn C, X and Ku Band RADAR
nn Test Equipment
nn Satellite MODEMs

Typical Application
Conversion Loss and IIP3
(Low Side LO, IF = 1890MHz)
LTC5549
RX 30
IFOUT 28
LNA RF IF IIP3
CONVERSION LOSS (dB), IIP3 (dBm)

26
LO
24
RX 22
LO 20
DUPLEXER
TX 18
LO DOWNMIXING
16
UPMIXING
TX 14
LO IFIN 12
PA RF IF
10 CONVERSION LOSS
8
LTC5549 6
5549 TA01a
3 4 5 6 7 8 9 10 11 12 13
RF FREQUENCY (GHz)
5549 TA01b

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LTC5549
Absolute Maximum Ratings Pin Configuration
(Note 1)
TOP VIEW
Supply Voltage (VCC)...................................................4V
Enable Input Voltage (EN).................–0.3V to VCC + 0.3V

GND

GND
LO
X2 Input Voltage (X2).......................–0.3V to VCC + 0.3V 12 11 10
LO Input Power (1GHz to 12GHz)................... ….+10dBm GND 1 9 VCC

LO Input DC Voltage ............................................. ±0.1V IF 2 13 8 X2

RF Power (2GHz to 14GHz).................................+20dBm
RF DC Voltage ........................................................ ±0.1V GND 3 7 EN
4 5 6
IF Power (0.5GHz to 6GHz).................................+20dBm

GND

RF

GND
IF DC Voltage.......................................................... ±0.1V
Operating Temperature Range (TC)......... –40°C to 105°C UDB PACKAGE
12-LEAD (2mm × 3mm) PLASTIC QFN
Storage Temperature Range................... –65°C to 150°C TJMAX = 150°C, θJC = 25°C/W
Junction Temperature (TJ)..................................... 150°C EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB

Order Information
Lead Free Finish
TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC5549IUDB#TRMPBF LTC5549IUDB#TRPBF LGTZ 12-Lead (2mm × 3mm) Plastic QFN –40°C to 105°C
TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/

DC Electrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TC = 25°C. VCC = 3.3V, EN = High, unless otherwise noted. Test circuit shown in
Figure 1. (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply Requirements
Supply Voltage (VCC) l 3.0 3.3 3.6 V
Supply Current Enabled EN = High, X2 = Low 115 136 mA
EN = High, X2 = High 130 155 mA
Disabled EN = Low 100 μA
Enable (EN) and LO Frequency Doubler (X2) Logic Inputs
Input High Voltage (On) l 1.2 V
Input Low Voltage (Off) l 0.3 V
Input Current –0.3V to VCC + 0.3V –30 100 μA
Chip Turn-On Time 0.2 μs
Chip Turn-Off Time 0.1 μs

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 LTC5549
AC Electrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TC = 25°C. VCC = 3.3V, EN = High, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for two-
tone IIP3 tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3)
PARAMETER CONDITIONS MIN TYP MAX UNITS
LO Frequency Range l 1 to 12 GHz
RF Frequency Range l 2 to 14 GHz
IF Frequency Range l 500 to 6000 MHz
RF Return Loss ZO = 50Ω, 2GHz to 13.6GHz >9 dB
LO Input Return Loss ZO = 50Ω, 1GHz to 12GHz >10 dB
IF Return Loss ZO = 50Ω, 0.7GHz to 6GHz >10 dB
LO Input Power X2 = Low –6 0 6 dBm
X2 = High –6 0 3 dBm
Downmixer Application with LO Doubler Off (X2 = Low)
Conversion Loss RF Input = 2GHz, LO = 3.89GHz 7.8 dB
RF Input = 5.8GHz, LO = 3.91GHz 8.0 dB
RF Input = 9GHz, LO = 7.11GHz 9.4 dB
RF Input = 12GHz, LO = 10.11GHz 10.8 dB
Conversion Loss vs Temperature TC = –40°C to 105°C, RF Input = 5.8GHz l 0.009 dB/°C
2-Tone Input 3rd Order Intercept RF Input = 2GHz, LO = 3.89GHz 26.0 dBm
(ΔfRF = 2MHz) RF Input = 5.8GHz, LO = 3.91GHz 28.2 dBm
RF Input = 9GHz, LO = 7.11GHz 24.4 dBm
RF Input = 12GHz, LO = 10.11GHz 22.8 dBm
SSB Noise Figure RF Input = 2GHz, LO = 3.89GHz 7.9 dB
RF Input = 5.8GHz, LO = 3.91GHz 8.1 dB
RF Input = 8.5GHz, LO = 6.61GHz 10.2 dB
RF Input = 10GHz, LO = 8.11GHz 10.4 dB
LO to RF Leakage fLO = 1GHz to 12GHz <–30 dBm
LO to IF Leakage fLO = 1GHz to 12GHz <–27 dBm
RF to LO Isolation fRF = 2GHz to 14GHz >45 dB
RF Input to IF Output Isolation fRF = 2GHz to 14GHz >35 dB
Input 1dB Compression RF Input = 5.8GHz, LO = 3.91GHz 14.3 dBm
Downmixer Application with LO Doubler On (X2 = High)
Conversion Loss RF Input = 5.8GHz, LO = 1.955GHz 8.2 dB
RF Input = 9GHz, LO = 3.555GHz 9.9 dB
RF Input = 12GHz, LO = 5.055GHz 11.9 dB
Conversion Loss vs. Temperature TC = –40°C to 105°C, RF Input = 5.8GHz l 0.009 dB/°C
2-Tone Input 3rd Order Intercept RF Input = 5.8GHz, LO = 1.955GHz 27.9 dBm
(ΔfRF = 2MHz) RF Input = 9GHz, LO = 3.555GHz 24.8 dBm
RF Input = 12GHz, LO = 5.055GHz 22.0 dBm
SSB Noise Figure RF Input = 5.8GHz, LO = 1.955GHz 9.6 dB
RF Input = 8.5GHz, LO = 3.305GHz 10.7 dB
RF Input = 10GHz, LO = 4.055GHz 12.6 dB
LO to RF Input Leakage fLO = 1GHz to 5GHz <–35 dBm
2LO to RF Input Leakage fLO = 1GHz to 5GHz ≤–28 dBm
LO to IF Output Leakage fLO = 1GHz to 5GHz <–30 dBm
2LO to IF Output Leakage fLO = 1GHz to 5GHz <–31 dBm
Input 1dB Compression fRF = 5.8GHz, fLO = 1.955GHz 13.8 dBm

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LTC5549
AC Electrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TC = 25°C. VCC = 3.3V, EN = High, PLO = 0dBm, PIF = –5dBm (–5dBm/tone for two-
tone IIP3 tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Upmixer Application with LO Doubler Off (X2 = Low)
Conversion Loss RF Output = 2GHz, LO = 3.89GHz 7.7 dB
RF Output = 5.8GHz, LO = 3.91GHz 7.8 dB
RF Output = 9GHz, LO = 7.11GHz 9.2 dB
RF Output = 12GHz, LO = 10.11GHz 10.7 dB
Conversion Loss vs Temperature TC = –40°C to 105°C, RF Output = 5.8GHz 0.009 dB/°C
Input 3rd Order Intercept (ΔfIF = 2MHz) RF Output = 2GHz, LO = 3.89GHz 25.0 dBm
RF Output = 5.8GHz, LO = 3.91GHz 24.4 dBm
RF Output = 9GHz, LO = 7.11GHz 23.9 dBm
RF Output = 12GHz, LO = 10.11GHz 19.9 dBm
SSB Noise Figure RF Output = 2GHz, LO = 3.89GHz 7.8 dB
RF Output = 5.8GHz, LO = 3.91GHz 8.8 dB
RF Output = 8.5GHz, LO = 6.61GHz 10.4 dB
RF Output = 10GHz, LO = 8.11GHz 11.1 dB
LO to RF Output Leakage fLO = 1GHz to 12GHz <–30 dBm
LO to IF Input Leakage fLO = 1GHz to 12GHz <–27 dBm
IF to LO Isolation fIF = 500MHz to 6GHz >45 dB
IF to RF Isolation fIF = 500MHz to 6GHz >40 dB
Input 1dB Compression RF Output = 5.8GHz, LO = 3.91GHz 15.5 dBm
Upmixer Application with LO Doubler On (X2 = High)
Conversion Loss RF Output = 5.8GHz, LO = 1.955GHz 8.1 dB
RF Output = 9GHz, LO = 3.555GHz 9.7 dB
RF Output = 12GHz, LO = 5.055GHz 11.8 dB
Conversion Loss vs Temperature TC = –40°C to 105°C, RF Output = 5.8GHz 0.009 dB/°C
2-Tone Input 3rd Order Intercept RF Output = 5.8GHz, LO = 1.955GHz 23.2 dBm
(ΔfIF = 2MHz) RF Output = 9GHz, LO = 3.555GHz 23.5 dBm
RF Output = 12GHz, LO = 5.055GHz 20.0 dBm
SSB Noise Figure RF Output = 5.8GHz, LO = 1.955GHz 10.9 dB
RF Output = 9GHz, LO = 3.555GHz 12.3 dB
RF Output = 10GHz, LO = 4.055GHz 12.7 dB
LO to RF Output Leakage fLO = 1GHz to 5GHz <–35 dBm
2LO to RF Output Leakage fLO = 1GHz to 5GHz <–30 dBm
LO to IF Input Leakage fLO = 1GHz to 5GHz <–30 dBm
2LO to IF Input Leakage fLO = 1GHz to 5GHz <–31 dBm
Input 1dB Compression RF Output = 5.8GHz, LO = 1.955GHz 15.4 dBm

Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 3: SSB noise figure measurements performed with a small-signal
may cause permanent damage to the device. Exposure to any Absolute noise source, bandpass filter and 2dB matching pad on input, with
Maximum Rating condition for extended periods may affect device bandpass filters on LO, and output.
reliability and lifetime.
Note 2: The LTC5549 is guaranteed functional over the –40°C to 105°C
case temperature range (θJC = 25°C/W).

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 LTC5549
Typical Performance Characteristics EN = high, test circuit shown in Figure 1.

Supply Current vs Case

Temperature Supply Current vs VCC
150 150
140 X2 = HIGH 140
X2 = HIGH
130 130
120 120
ICC (mA)

ICC (mA)
110 110
X2 = LOW
100 X2 = LOW 100
90 90
80 –40°C
VCC = 3.0V 80
25°C
70 VCC = 3.3V 70 85°C
VCC = 3.6V 105°C
60 60
–40 –20 0 20 40 60 80 100 120 3 3.1 3.2 3.3 3.4 3.5 3.6
CASE TEMPERATURE (°C) SUPPLY VOLTAGE (V)
5549 G01 5549 G02

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LTC5549
Typical Performance Characteristics 2GHz to 13GHz downmixer application.
VCC = 3.3V, EN = high, X2 = low, TC = 25°C, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), IF = 1.89GHz,
unless otherwise noted. Test circuit shown in Figure 1.
Conversion Loss and IIP3 vs Case Conversion Loss and IIP3 vs Case
Temperature (Low Side LO) Temperature (High Side LO)
30 28
28 26

CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

IIP3
26 24 IIP3
24 22
22 20
20 –40°C
18 –40°C
25°C
18 25°C
85°C 16 85°C
16 105°C
14 105°C
14
12
12 CONVERSION LOSS CONVERSION LOSS
10 10
8 8
6 6
3 4 5 6 7 8 9 10 11 12 13 2 3 4 5 6 7 8 9 10 11
RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G03 5549 G04

Conversion Loss and IIP3 vs LO Conversion Loss and IIP3 vs LO

Power (Low Side LO) Power (High Side LO)
30 28
28 IIP3 26
CONVERSION LOSS (dB), IIP3 (dBm)
CONVERSION LOSS (dB), IIP3 (dBm)

26 24 IIP3
24 22
22 20
20
18
18 –6dBm
0dBm 16 –6dBm
16 6dBm 0dBm
14 6dBm
14
12 12
CONVERSION LOSS 10 CONVERSION LOSS
10
8 8
6 6
3 4 5 6 7 8 9 10 11 12 13 2 3 4 5 6 7 8 9 10 11
RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G05 5549 G06

Conversion Loss and IIP3 Conversion Loss and IIP3 vs

vs Supply Voltage (Low Side LO) Supply Voltage (High Side LO)
30 28
28 26
CONVERSION LOSS (dB), IIP3 (dBm)
CONVERSION LOSS (dB), IIP3 (dBm)

26 IIP3
24 IIP3
24 22
22 20
20
3.0V 18
18 3.0V
3.3V 16
16 3.6V 3.3V
14 3.6V
14
12
12 CONVERSION LOSS CONVERSION LOSS
10 10
8 8
6 6
3 4 5 6 7 8 9 10 11 12 13 2 3 4 5 6 7 8 9 10 11
RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G07 5549 G08

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 LTC5549
Typical Performance Characteristics 2GHz to 13GHz downmixer application.
VCC = 3.3V, EN = high, X2 = low, TC = 25°C, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), IF = 1.89GHz,
unless otherwise noted. Test circuit shown in Figure 1.
Conversion Loss and IIP3 vs IF
Frequency (Low Side LO) Input P1dB vs RF Frequency
30 16

27 15 LOW SIDE LO
CONVERSION LOSS (dB), IIP3 (dBm)

IIP3
24 14

INPUT PIdB (dBm)

21 13
RF = 5.8GHz
18 RF = 9.8GHz 12 HIGH SIDE LO

15 11

12 CONVERSION LOSS 10

9 9

6 8
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 2 3 4 5 6 7 8 9 10 11 12 13
IF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G09 5549 G10

LO Leakage RF Isolation
–10 70
65
60 RF-LO
–20
55
LO LEAKAGE (dBm)

RF ISOLATION (dB)

LO-IF
50
HS LO
–30 45
LS LO
40
LO-RF
35
–40 RF-IF
30
25
–50 20
1 2 3 4 5 6 7 8 9 10 11 12 2 3 4 5 6 7 8 9 10 11 12 13
LO FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G11 5549 G12

5.8GHz Conversion Loss

Histogram 5.8GHz IIP3 Histogram
70 35
85°C 85°C
25°C 25°C
60 30 –40°C
–40°C

50 25
DISTRIBUTION (%)

DISTRIBUTION (%)

40 20

30 15

20 10

10 5

0 0
7.2 7.4 7.6 7.8 8.0 8.2 8.4 8.6 26.2 26.8 27.4 28 28.6 29.2 29.8
CONVERSION LOSS (dB) CONVERSION LOSS (dB)
5549 G13 5549 G14

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LTC5549
Typical Performance Characteristics 2GHz to 13GHz downmixer application with LO
frequency doubler enabled. VCC = 3.3V, EN = high, X2 = high, TC = 25°C, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for two-tone IIP3
tests, Δf = 2MHz), IF = 1.89GHz, unless otherwise noted. Test circuit shown in Figure 1.
Conversion Loss and IIP3 vs Case Conversion Loss and IIP3 Conversion Loss and IIP3
Temperature (Low Side LO) vs LO Power (Low Side LO) vs Supply Voltage (Low Side LO)
30 30 30
28 28 28
CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

26 IIP3 26 IIP3 26 IIP3
24 24 24
22 22 22
20 –40°C –6dBm
20 20
25°C 0dBm 3.0V
18 18 3dBm 18
85°C 3.3V
16 105°C 16 16 3.6V
14 14 14
12 CONVERSION LOSS 12 CONVERSION LOSS 12 CONVERSION LOSS
10 10 10
8 8 8
6 6 6
3 4 5 6 7 8 9 10 11 12 13 3 4 5 6 7 8 9 10 11 12 13 3 4 5 6 7 8 9 10 11 12 13
RF FREQUENCY (GHz) RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G15 5549 G16 5549 G17

Conversion Loss and IIP3 vs Case Conversion Loss and IIP3 Conversion Loss and IIP3
Temperature (High Side LO) vs LO Power (High Side LO) vs Supply Voltage (High Side LO)
28 28 28
26 26 26
CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

24 IIP3 24 IIP3 24 IIP3
22 22 22
20 –40°C 20 20
18 25°C 18 –6dBm 3.0V
18
85°C 0dBm 3.3V
16 105°C 16 3dBm 16 3.6V
14 14 14
12 CONVERSION LOSS 12 CONVERSION LOSS 12
CONVERSION LOSS
10 10 10
8 8 8
6 6 6
2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10
RF FREQUENCY (GHz) RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G18 5549 G19 5549 G20

Conversion Loss and IIP3

vs IF Frequency (Low Side LO) Input P1dB vs RF Frequency LO and 2LO Leakage to IF
30 15 –10
LOW SIDE LO
27
CONVERSION LOSS (dB), IIP3 (dBm)

14
LO AND 2LO LEAKAGE (dBm)

24 IIP3 –20
13
INPUT P1dB (dBm)

21 HIGH SIDE LO
RF = 5.8GHz 12
18 –30 2LO-IF
RF = 9.8GHz
11
15
10
12 CONVERSION LOSS –40

9 9 LO-IF

6 8 –50
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 2 3 4 5 6 7 8 9 10 11 12 13 1 2 3 4 5
IF FREQUENCY (GHz) RF FREQUENCY (GHz) LO FREQUENCY (GHz)
5549 G21 5549 G22 5549 G23

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 LTC5549
Typical Performance Characteristics 2GHz to 13GHz upmixer application.
VCC = 3.3V, EN = high, X2 = low, TC = 25°C, PLO = 0dBm, PIF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), IF = 1.89GHz,
unless otherwise noted. Test circuit shown in Figure 1.
Conversion Loss and IIP3 vs Case Conversion Loss and IIP3 Conversion Loss and IIP3
Temperature (Low Side LO) vs LO Power (Low Side LO) vs Supply Voltage (Low Side LO)
28 28 28
26 IIP3 26 IIP3 26
IIP3
CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

24 24 24
22 22 22
20 –40°C 20 20
25°C –6dBm 3.0V
18 18 18
85°C 0dBm 3.3V
16 105°C 16 6dBm 16 3.6V
14 14 14
12 CONVERSION LOSS 12 12
CONVERSION LOSS CONVERSION LOSS
10 10 10
8 8 8
6 6 6
3 4 5 6 7 8 9 10 11 12 13 3 4 5 6 7 8 9 10 11 12 13 3 4 5 6 7 8 9 10 11 12 13
RF FREQUENCY (GHz) RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G24 5549 G25 5549 G26

Conversion Loss and IIP3 vs Case Conversion Loss and IIP3 Conversion Loss and IIP3
Temperature (High Side LO) vs LO Power (High Side LO) vs Supply Voltage (High Side LO)
28 28 28
26 26 26
CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

24 IIP3 24 IIP3 24 IIP3
22 22 22
20 20 20
18 –40°C 18 –6dBm 18 3.0V
25°C 0dBm 3.3V
16 85°C 16 6dBm 16 3.6V
14 105°C 14 14
12 12 12
CONVERSION LOSS CONVERSION LOSS CONVERSION LOSS
10 10 10
8 8 8
6 6 6
2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10
RF FREQUENCY (GHz) RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G27 5549 G28 5549 G29

Conversion Loss and IIP3

vs IF Frequency (Low Side LO) Input P1dB vs IF Frequency IF Isolation
30 17 80
28 IIP3
CONVERSION LOSS (dB), IIP3 (dBm)

26 16 70
24 IF-LO
15
INPUT P1dB (dBm)

IF ISOLATION (dB)

22 60
20 14
RF = 5.8GHz
18 RF = 9.8GHz 50
16 13
14 40 IF-RF
12
12 CONVERSION LOSS
10 HS LO RF = 5.8GHz 30
11
8 LS LO RF = 9.8GHz
6 10 20
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6
IF FREQUENCY (GHz) IF FREQUENCY (GHz) IF FREQUENCY (GHz)
5549 G30 5549 G31 5549 G32

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LTC5549
Typical Performance Characteristics 2GHz to 13GHz upmixer application with LO
frequency doubler enabled. VCC = 3.3V, EN = high, X2 = high, TC = 25°C, PLO = 0dBm, PIF = –5dBm (–5dBm/tone for two-tone IIP3
tests, Δf = 2MHz), output measured at 5.8GHz, unless otherwise noted. Test circuit shown in Figure 1.
Conversion Loss and IIP3 vs Case Conversion Loss and IIP3 vs LO Conversion Loss and IIP3 vs
Temperature (Low Side LO) Power (Low Side LO) Supply Voltage (Low Side LO)
28 28 28
26 26 26
IIP3 IIP3
CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

IIP3
24 24 24
22 22 22
20 –40°C 20 20
–6dBm 3.0V
18 25°C 18 0dBm 18
85°C 3.3V
16 16 3dBm 16 3.6V
105°C
14 14 14
12 CONVERSION LOSS 12 CONVERSION LOSS 12
CONVERSION LOSS
10 10 10
8 8 8
6 6 6
4 5 6 7 8 9 10 11 12 13 4 5 6 7 8 9 10 11 12 13 4 5 6 7 8 9 10 11 12 13
RF FREQUENCY (GHz) RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G33 5549 G34 5549 G35

Conversion Loss and IIP3 vs Case Conversion Loss and IIP3 vs LO Conversion Loss and IIP3 vs
Temperature (High Side LO) Power (High Side LO) Supply Voltage (High Side LO)
26 26 26
24 24 24
IIP3
CONVERSION LOSS (dB), IIP3 (dBm)
CONVERSION LOSS (dB), IIP3 (dBm)

CONVERSION LOSS (dB), IIP3 (dBm)

22 IIP3 IIP3
22 22
20 20 20
–40°C –6dBm 3.0V
18 25°C 18 18
0dBm 3.3V
16 85°C 16 3dBm 16 3.6V
105°C
14 14 14
12 12 CONVERSION LOSS 12
CONVERSION LOSS
10 10 10 CONVERSION LOSS

8 8 8
6 6 6
2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10
RF FREQUENCY (GHz) RF FREQUENCY (GHz) RF FREQUENCY (GHz)
5549 G36 5549 G37 5549 G38

Conversion Loss and IIP3 vs IF

Frequency (Low Side LO) Input P1dB vs IF Frequency LO and 2LO Leakage to RF
28 17 –10
26 IIP3
CONVERSION LOSS (dB), IIP3 (dBm)

16
24
LO AND 2LO LEAKAGE (dBm)

22 –20
15
INPUT P1dB (dBm)

20 2LO-RF
RF = 5.8GHz 14
18 RF = 9.8GHz –30
16 13
14
12 CONVERSION LOSS 12
–40
10
11 HS LO RF = 5.8GHz LO-RF
8 LS LO RF = 9.8GHz
6 10 –50
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 1 2 3 4 5
IF FREQUENCY (GHz) IF FREQUENCY (GHz) LO FREQUENCY (GHz)
5549 G39 5549 G40 5549 G41

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 LTC5549
Pin Functions
GND (Pins 1, 3, 4, 6, 10, 12, Exposed Pad Pin 13): EN (Pin 7): Enable Pin. When the voltage to this pin is
Ground. These pins must be soldered to the RF ground greater than 1.2V, the mixer is enabled. When the input
on the circuit board. The exposed pad metal of the pack- voltage is less than 0.3V, the mixer is disabled. Typical
age provides both electrical contact to ground and good current drawn is less than 30μA. This pin has an internal
thermal contact to the printed circuit board. 376kΩ pull-down resistor.
IF (Pin 2): Single-Ended Terminal for the IF Port. This pin X2 (Pin 8): Digital Control Pin for LO Frequency Doubler.
is internally connected to the primary side of the IF trans- When the voltage to this pin is greater than 1.2V, the LO
former, which has low DC resistance to ground. A series frequency doubler is enabled. When the input voltage
DC blocking capacitor should be used to avoid damage to is less than 0.3V, the LO frequency doubler is disabled.
the integrated transformer when DC voltage is present. The Typical current drawn is less than 30μA. This pin has an
IF port is impedance matched from 500MHz to 6GHz, as internal 376kΩ pull-down resistor.
long as the LO is driven with a 0 ±6dBm source between
VCC (Pin 9): Power Supply Pin. This pin must be externally
1GHz and 12GHz. connected to a regulated 3.3V supply, with a bypass capaci-
RF (Pin 5): Single-Ended Terminal for the RF Port. This tor located close to the pin. Typical current consumption
pin is internally connected to the primary side of the RF is 115mA.
transformer, which has low DC resistance to ground. A LO (Pin 11): Input for the Local Oscillator (LO). The LO
series DC blocking capacitor should be used to avoid signal is applied through this pin. A series DC blocking
damage to the integrated transformer when DC voltage is capacitor should be used. Typical DC voltage at this pin
present. The RF port is impedance matched from 2GHz to is 1.6V.
14GHz as long as the LO is driven with a 0 ±6dBm source
between 1GHz and 12GHz.

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LTC5549
Block Diagram

2
LTC5549 IF

X2
5
RF LO
11
AMP
LO

MIXER
CORE

REF/BIAS

EN X2 VCC
7 8 9
5549 BD
GND PINS ARE NOT SHOWN.

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 LTC5549
Test Circuit

IF
50Ω

3 2 1
GND IF GND

4 GND LTC5549 GND 12

C5
RF 13 LO
5 RF LO 11
50Ω GND 50Ω
C1 ZO = 50Ω ZO = 50Ω C4
L = 1.4mm L = 3.55mm

6 GND GND 10

EN X2 VCC
7 8 9

EN VCC
(3.0V TO 3.6V)
X2 C2 C3

5549 F01

REF DES VALUE SIZE VENDOR COMMENT

C1, C4 0.15pF 0402 AVX ACCU-P 04021JR15ZBS
C2, C5 22pF 0402 AVX
C3 1µF 0603 AVX

Figure 1. Standard Test Circuit Schematic

IF
50Ω

3 2 1
GND IF GND
4 GND LTC5549 GND 12

C5
RF 13 LO
5 RF LO 11
50Ω GND 50Ω
C1 ZO = 50Ω ZO = 50Ω C4
L = 1.4mm L = 3.55mm
6 GND GND 10
EN X2 VCC
7 8 9
EN VCC
(0V/3.3V) (3.0V TO 3.6V)
T2
C2 C3
(0V/3.3V)
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5549 F01

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LTC5549
Applications Information
Introduction LTC5549

The LTC5549 consists of a high linearity double-balanced

mixer core, LO buffer amplifier, LO frequency doubler RF
and bias/enable circuits. See the Block Diagram section 50Ω
RF
5
for a description of each pin function. The RF, LO and IF C1 ZO = 50Ω
are single-ended terminals. The LTC5549 can be used L = 1.4mm

as a frequency downconverter where the RF is used as 5549 F03

an input and IF is used as an output. It can also be used Figure 3. Simplified RF Port Interface Schematic
as a frequency upconverter where the IF is used as an
input and RF is used as an output. Low side or high side 0

LO injection can be used. The evaluation circuit and the

5
evaluation board layout are shown in Figure 1 and Figure 2,
respectively.

RETURN LOSS (dB)

10

15

20
LOW SIDE LO
IF = 900MHz
25
IF = 1890MHz
IF = 4000MHz
30
2 3 4 5 6 7 8 9 10 11 12 13 14
RF FREQUENCY (GHz)
5549 F04a

(a)
0
LOW SIDE LO
IF = 900MHz
5 IF = 1890MHz
IF = 4000MHz
10
RETURN LOSS (dB)

15

20
5549 F02

Figure 2. Evaluation Board Layout 25

RF Port 30

The mixer’s RF port, shown in Figure 3, is connected to the 35

2 3 4 5 6 7 8 9 10 11
primary winding of an integrated transformer. The primary RF FREQUENCY (GHz)

side of the RF transformer is DC-grounded internally and 5549 F04a

(b)
the DC resistance of the primary side is approximately
3.2Ω. A DC blocking capacitor is needed if the RF source Figure 4. RF Port Return Loss (a) C1 = 0.15pF (b) C1 Open
has DC voltage present. The secondary winding of the
RF transformer is internally connected to the mixer core. The measured RF input return loss is shown in Figure 4
The RF port is broadband matched to 50Ω from 2GHz to for IF frequencies of 900MHz, 1890MHz and 4GHz.
14GHz with a 0.15pF shunt capacitor (C1) located 1.4mm
LO Input
away from the RF pin. The RF port is 50Ω matched from
2GHz to 10GHz without C1. An LO signal between –6dBm The mixer’s LO input circuit, shown in Figure 5, consists
and 6dBm is required for good RF impedance matching. of a single-ended to differential conversion, high speed
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14 For more information www.linear.com/LTC5549

 LTC5549
Applications Information
The IF port is broadband matched to 50Ω from 500MHz to
LTC5549
6GHz. An LO signal between -6dBm and 6dBm is required
for good IF impedance matching. Frequencies outside of
X2 this range can be used with degraded performance.
C5 LOIN
LO
11 The measured IF port return loss is shown in Figure 8.
C4
0
X2 = LOW, EN = HIGH
X2 = LOW, EN = LOW
5 X2 = HIGH, EN = HIGH
X2 VCC
8 9

RETURN LOSS (dB)

5549 F05 10

Figure 5. Simplified LO Input Schematic 15

limiting differential amplifier and an LO frequency doubler. 20

The LTC5549’s LO amplifier is optimized for the 1GHz 25

to 12GHz LO frequency range. LO frequencies above or
below this frequency range may be used with degraded 30
1 2 3 4 5 6 7 8 9 10 11 12 13
performance. The LO frequency doubler is controlled by LO FREQUENCY (GHz)
a digital voltage input at X2 (Pin 8). When the X2 voltage 5549 F06

is higher than 1.2V, the LO frequency doubler is enabled. Figure 6. LO Input Return Loss
When X2 is left open or its voltage is lower than 0.5V, the
LO frequency doubler is disabled.
LTC5549
The mixer’s LO input is connected to a singled-ended to
differential buffer and ESD devices. The DC voltage at the
LO input is about 1.6V. A DC blocking capacitor is required IF
IF
for the LO circuit to operate properly. 2

The LO is 50Ω matched from 1GHz to 12GHz. With a

0.15pF shunt capacitor (C4) located 3.55mm away from 5549 F07

the LO pin. The LO port is 50Ω matched from 1GHz to

Figure 7. Simplified IF Port Interface Schematic
8.4GHz without C4. External matching components may
be needed for extended LO operating frequency range.
0
The measured LO input return loss is shown in Figure 6.
5
The nominal LO input level is 0dBm, although the limiting
amplifiers will deliver excellent performance over a ±6dBm 10
RETURN LOSS (dB)

input power range. 15

20
IF Port
25
The mixer’s IF port, shown in Figure 7, is connected to the 30
primary winding of an integrated transformer. The primary 35
side of the IF transformer is DC-grounded internally and
40
the DC resistance is approximately 6.2Ω. A DC blocking 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6

capacitor is needed if the IF source has DC voltage present. IF FREQUENCY (GHz)

The secondary winding of the IF transformer is internally

5549 F08

Figure 8. IF Port Return Loss

connected to the mixer core.
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LTC5549
Applications Information
Enable Interface the X2 voltage must be higher than 1.2V. The X2 voltage
at the pin should never exceed VCC by more than 0.3V. If
Figure 9 shows a simplified schematic of the EN pin in-
this should occur, the supply current could be sourced
terface. To enable the chip, the EN voltage must be higher
than 1.2V. The voltage at the EN pin should never exceed through the ESD diode, potentially damaging the IC. If the
VCC by more than 0.3V. If this should occur, the supply X2 pin is left floating, its voltage will be pulled low by the
current could be sourced through the ESD diode, potentially internal pull-down resistor and the LO frequency doubler
damaging the IC. If the EN pin is left floating, its voltage will be disabled.
will be pulled low by the internal pull-down resistor and
Supply Voltage Ramping
the chip will be disabled.
Fast ramping of the supply voltage can cause a current
X2 Interface glitch in the internal ESD protection circuits. Depending on
the supply inductance, this could result in a supply volt-
Figure 10 shows a simplified schematic of the X2 pin
age transient that exceeds the maximum rating. A supply
interface. To enable the integrated LO frequency doubler,
voltage ramp time of greater than 1ms is recommended.

LTC5549 LTC5549
VCC VCC
9 9

EN X2
7 BIAS 8

5549 F09 5549 F10

Figure 9. Simplified Enable Input Circuit Figure 10. Simplified X2 Interface Circuit

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16 For more information www.linear.com/LTC5549

 LTC5549
Typical Application
Due to the wideband nature of the RF, LO and IF ports, in this manner only requires that the input and output
the LTC5549 may be used as an upmixer even when the frequencies are within the specified frequency ranges.
lower (IF) input frequency is applied to the RF port and One example is shown in Figure 11, where the RF input
the higher (RF) output is taken from the IF port. Operation ranges from 1.6GHz to 4.5GHz and the IF output is 5.2GHz.

LTC5549
1.6GHz to 4.5GHz 5.2GHz
RF IF

LO

3.6GHz to 0.7GHz

5549 F11a

(a) Application Configuration

30
28
CONVERSION LOSS (dB), IIP3 (dBm)

26 IIP3
24
22
20
18
16
14
12
CONVERSION LOSS
10
8
1.5 2 2.5 3 3.5 4 4.5
INPUT FREQUENCY (GHz)
5549 F11b

(b) Conversion Loss and IIP3 vs Input Frequency

(Low Side LO, Output = 5.2GHz)

Figure 11. An Upmixer Application with Input at the RF Port and Output at the IF Port

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LTC5549
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.

UDB Package
Variation A
12-LeadUDBPlastic QFN (3mm × 2mm)
Package
(Reference Variation:
LTC DWG # 05-08-1985
A Rev Ø)
12-Lead Plastic QFN (3mm × 2mm)
(Reference LTC DWG # 05-08-1985 Rev Ø)

0.25 ±0.05
0.85 ±0.05

0.65 ±0.05
0.77 ±0.05
0.05 REF
2.50 ±0.05
DETAIL B DETAIL B
PACKAGE 0.25 ±0.10
OUTLINE
0.25 ±0.05
0.50 BSC
0.75 ±0.05 0.77 ±0.10
3.50 ±0.05 0.05 REF
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS DETAIL A
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED R = 0.13 0.15 REF
TYP 0.60 ±0.10
10 12
0.40 ±0.10
9 1 0.40 REF
2.00 ±0.10
DETAIL A
7 3
0.40 ±0.10
6 4
3.00 ±0.10 0.50 ±0.10
0.50 ±0.10 (UDB12) DFN 0814 REV 0

0.75 ±0.05 0.25 ±0.05

0.20 REF
0.50 BSC
BOTTOM VIEW—EXPOSED PAD

SIDE VIEW
0.00 – 0.05
NOTE:
1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE

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18 For more information www.linear.com/LTC5549

 LTC5549
Revision History
REV DATE DESCRIPTION PAGE NUMBER
A 9/15 Order part number correction. 2

5549fa

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
For more
tion that the interconnection information
of its circuits www.linear.com/LTC5549
as described herein will not infringe on existing patent rights. 19
LTC5549
Typical Application
5GHz to 14GHz Downconversion Conversion Loss and IIP3 vs Input
Frequency (Low Side LO, IF = 4GHz)
30
ZO = 50Ω LTC5549
L = 1.4mm 28 IIP3
5GHz to 14GHz 4GHz

CONVERSION LOSS (dB), IIP3 (dBm)

RF IF 26
24
0.15pF
LO 22
20
DOWNMIXING
ZO = 50Ω 18
UPMIXING
L = 3.55mm 16
14
22pF 12
0.15pF
10
1GHz to 10GHz 8 CONVERSION LOSS
6
5549 TA02a 5 6 7 8 9 10 11 12 13 14
RF FREQUENCY (GHz)
5549 TA02b

Related Parts
PART NUMBER DESCRIPTION COMMENTS
Mixers and Modulators
LTC5551 300MHz to 3.5GHz Ultrahigh Dynamic Range +36dBm IIP3; 2.4dB Gain, <10dB NF, 0dBm LO Drive, +18dBm P1dB,
Downconverting Mixer 670mW Power Consumption
LTC5567 400MHz to 4GHz, Active Downconverting Mixer 1.9dB Gain, 26.9dBm IIP3 and 11.8dB NF at 1950MHz, 3.3V/89mA Supply
LTC5577 300MHz to 6GHz High Signal Level Active 50Ω Matched Input from 1.3GHz to 4.3GHz, 30dBm IIP3, 0dB Gain,
Downconverting Mixer >40dB LO-RF Isolation, 0dBm LO Drive
LTC5510 1MHz to 6GHz Wideband High Linearity Active 50Ω Matched Input from 30MHz to 6GHz, 27dBm OIP3, 1.5dB Gain,
Mixer Up- or Down-Conversion
LTC5544 4GHz to 6GHz Downconverting Mixer 7.5dB Gain, >25dBm IIP3 and 10dB NF, 3.3V/200mA Supply
LT5578 400MHz to 2.7GHz Upconverting Mixer 27dBm OIP3 at 900MHz, 24.2dBm at 1.95GHz, Integrated RF Output Transformer
LT5579 1.5GHz to 3.8GHz Upconverting Mixer 27.3dBm OIP3 at 2.14GHz, NF = 9.9dB, 3.3V Supply, Single-Ended LO and RF Ports
LTC5576 3GHz to 8GHz High Linearity Active 25dBm OIP3, –0.6dB Gain, 14.1dB NF, –154dBm/Hz Output Noise Floor, –28dBm LO
Upconverting Mixer Leakage at 8GHz
Amplifiers
LTC6430-20 High Linearity Differential IF Amp 20MHz to 2GHz Bandwidth, 20.8dB Gain, 51dBm OIP3, 2.9dB NF at 240MHz
LTC6431-20 High Linearity Single-Ended IF Amp 20MHz to 1.4GHz Bandwidth, 20.8dB Gain, 46.2dBm OIP3, 2.6dB NF at 240MHz
RF Power Detectors
LTC5564 15GHz Ultra Fast 7ns Response Time RF 600MHz to 15GHz, –24dB to 16dBm Input Power Range, 9ns Comparator Response
Detector with Comparator Time, 125°C Version
LT5581 6GHz Low Power RMS Detector 40dB Dynamic Range, ±1dB Accuracy Over Temperature, 1.5mA Supply Current
LTC5582 40MHz to 10GHz RMS Detector ±0.5dB Accuracy Over Temperature, ±0.2dB Linearity Error, 57dB Dynamic Range
LTC5583 Dual 6GHz RMS Power Detector Up to 60dB Dynamic Range, ±0.5dB Accuracy Over Temperature, >50dB Isolation
RF PLL/Synthesizer with VCO
LTC6948 Ultralow Noise, Low Spurious Frac-N PLL with 373MHz to 6.39GHz, –157dBc/Hz WB Phase Noise Floor, –274dBc/Hz Normalized
Integrated VCO In-Band 1/f Noise

5549fa

20 Linear Technology Corporation

LT 0915 REV A • PRINTED IN USA

1630 McCarthy Blvd., Milpitas, CA 95035-7417

For more information www.linear.com/LTC5549
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTC5549  LINEAR TECHNOLOGY CORPORATION 2015