LTC5544_技术文档

LTC5544

4GHz to 6GHz

High Dynamic Range

Downconverting Mixer

FeaTures

DescripTion

TheLTC^®5544ispartofafamilyofhighdynamicrange,high

gainpassivedownconvertingmixerscoveringthe600MHz

to 6GHz frequency range. The LTC5544 is optimized for

4GHz to 6GHz RF applications. The LO frequency must

fall within the 4.2GHz to 5.8GHz range for optimum

performance. A typical application is a WiMAX receiver

with a 5.15GHz to 5.35GHz RF input and low side LO.

n

Conversion Gain: 7.4dB at 5250MHz

n

IIP3: 25.9dBm at 5250MHz

n

Noise Figure: 11.3dB at 5250MHz

n

High Input P1dB

n

IF Bandwidth Up to 1GHz

n

640mW Power Consumption

n

Shutdown Pin

n

50Ω Single-Ended RF and LO Inputs

TheLTC5544isdesignedfor3.3Voperation, however;the

IF amplifier can be powered with 5V for the higher P1dB.

n

+2dBm LO Drive Level

n

High LO-RF and LO-IF Isolation

n

TheLTC5544’shighlevelofintegrationminimizesthetotal

solution cost, board space and system-level variation,

while providing the highest dynamic range for demanding

receiver applications.

–40°C to 105°C Operation (T )

C

Small Solution Size

16-Lead (4mm × 4mm) QFN package

applicaTions

High Dynamic Range Downconverting Mixer Family

n

5GHz WiMAX/WLAN Receiver

PART#

RF RANGE

LO RANGE

n

4.9GHz Public Safety Bands

LTC5540

LTC5541

LTC5542

LTC5543

LTC5544

600MHz to 1.3GHz

1.3GHz to 2.3GHz

1.6GHz to 2.7GHz

2.3GHz to 4GHz

4GHz to 6GHz

700MHz to 1.2GHz

1.4GHz to 2.0GHz

1.7GHz to 2.5GHz

2.4GHz to 3.6GHz

4.2GHz to 5.8GHz

n

4.9GHz to 6GHz Military Communications

n

Point-to-Point Broadband Communications

n

Radar Systems

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

Typical applicaTion

Wideband Conversion Gain, IIP3

and NF vs IF Output Frequency

Wideband Receiver

240MHz

SAW

1nF

LTC6416

LTC2208

8.5

8.3

8.1

7.9

7.7

7.5

7.3

7.1

6.9

6.7

6.5

29

27

25

23

21

19

17

15

13

11

9

V

IF

CCIF

1nF

150nH

ADC

AMP

3.3V or 5V

150nH

22pF

IIP3

1µF

+

–

f

= 5010MHz

LO

IF

P

= 2dBm

RF = 5250 35MHz

TEST CIRCUIT IN FIGURE 1

LTC5544

IMAGE

BPF

IF

1.2pF

0.6pF

RF

5150MHz

TO

G

C

RF

SYNTH

LNA

LO

5350MHz

LO

5010MHz

2.2nH

NF

SHDN

(0V/3.3V)

BIAS

SHDN

205 215 225 235 245 255 265 275

V

CC2

CC1

IF OUTPUT FREQUENCY (MHz)

5544 TA01b

V

3.3V

CC

1µF

22pF

5544 TA01a

5544f

1

LTC5544

absoluTe MaxiMuM raTings

pin conFiguraTion

(Note 1)

TOP VIEW

Mixer Supply Voltage (V , V )...........................4.0V

CC1 CC2

+

–

IF Supply Voltage (IF , IF ) ......................................5.5V

Shutdown Voltage (SHDN)................–0.3V to V +0.3V

CC

16 15 14 13

IF Bias Adjust Voltage (IFBIAS).........–0.3V to V +0.3V

GND

RF

1

2

3

4

12 TEMP

11 GND

CC

LO Bias Adjust Voltage (LOBIAS)......–0.3V to V +0.3V

CC

17

GND

CT

LO

10

9

LO Input Power (4GHz to 6GHz)...........................+9dBm

LO Input DC Voltage............................................... 0.1V

RF Input Power (4GHz to 6GHz)......................... +15dBm

RF Input DC Voltage............................................... 0.1V

TEMP Diode Continuous DC Input Current.............10mA

TEMP Diode Input Voltage ........................................ 1V

SHDN

GND

5

6

7

8

UF PACKAGE

16-LEAD (4mm × 4mm) PLASTIC QFN

Operating Temperature Range (T )........ –40°C to 105°C

T

= 150°C, θ = 8°C/W

JC

EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB

C

JMAX

Storage Temperature Range .................. –65°C to 150°C

Junction Temperature (T ) .................................... 150°C

J

orDer inForMaTion

LEAD FREE FINISH

TAPE AND REEL

PART MARKING

PACKAGE DESCRIPTION

16-Lead (4mm x 4mm) Plastic QFN

CASE TEMPERATURE RANGE

–40°C to 105°C

LTC5544IUF#PBF

LTC5544IUF#TRPBF

5544

Consult LTC Marketing for parts specified with wider operating temperature ranges.

Consult LTC Marketing for information on non-standard 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/

ac elecTrical characTerisTics ^V_CC= 3.3V, V_CCIF= 3.3V, SHDN = Low, T_C= 25°C, P_LO= 2dBm,

unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

LO Input Frequency Range

RF Input Frequency Range

4200 to 5800

MHz

Low Side LO

High Side LO

4200 to 6000

4000 to 5800

MHz

IF Output Frequency Range

RF Input Return Loss

LO Input Return Loss

IF Output Impedance

LO Input Power

Requires External Matching

5 to 1000

>12

MHz

dB

Z = 50Ω, 4000MHz to 6000MHz

O

Z = 50Ω, 4200MHz to 5800MHz

O

>12

dB

||

R C

Differential at 240MHz

332Ω 1.7pF

f

= 4200MHz to 5800MHz

–1

2

5

dBm

dB

LO

RF

LO to RF Leakage

= 4200MHz to 5800MHz, Requires C2

= 4200MHz to 5800MHz

<–30

<–21

>38

LO to IF Leakage

RF to LO Isolation

RF to IF Isolation

= 4000MHz to 6000MHz

>29

dB

5544f

2

LTC5544

ac elecTrical characTerisTics ^V_CC= 3.3V, V_CCIF= 3.3V, SHDN = Low, T_C= 25°C, P_LO= 2dBm,

P_RF= –3dBm (–3dBm/tone for 2-tone tests),unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3)

Low Side LO Downmixer Application: RF = 4200MHz to 6000MHz, IF = 240MHz, f = f – f

LO

RF

IF

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Conversion Gain

RF = 4900MHz

RF = 5250MHz

RF = 5800MHz

7.9

7.4

6.4

6.0

dB

Conversion Gain Flatness

RF = 5250MHz 30MHz, LO = 5010MHz, IF = 240 30MHz

0.15

dB

Conversion Gain vs Temperature

T = –40°C to 105°C, RF = 5250MHz

C

–0.007

dB/°C

rd

2-Tone Input 3 Order Intercept

RF = 4900MHz

RF = 5250MHz

RF = 5800MHz

25.4

25.9

25.8

(∆f = 2MHz)

dBm

nd

2-Tone Input 2 Order Intercept

f

= 5371MHz, f = 5130MHz,

43.2

RF1

RF2

(∆f = 241MHz, f = f – f

)

= 5010MHz

LO

IM2

RF1

RF2

SSB Noise Figure

RF = 4900MHz

RF = 5250MHz

RF = 5800MHz

10.3

11.3

12.8

dB

SSB Noise Figure Under Blocking

2RF – 2LO Output Spurious Product

f

= 5250MHz, f = 5010MHz,

BLOCK

16.9

–58.3

–77

RF

LO

= 4910MHz, P

= 5dBm

BLOCK

f

= 5130MHz at –10dBm, f = 5010MHz, f = 240MHz

dBc

RF

LO

IF

(f = f + f /2)

RF

LO

IF

3RF – 3LO Output Spurious Product

(f = f + f /3)

f

= 5090MHz at –10dBm, f = 5010MHz, f = 240MHz

LO IF

RF

LO

IF

Input 1dB Compression

RF = 5250MHz, V

= 3.3V

= 5V

11.4

14.6

dBm

CCIF

High Side LO Downmixer Application: RF = 4000MHz to 5800MHz, IF = 240MHz, f = f + f

IF

LO

RF

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Conversion Gain

RF = 4500MHz

RF = 4900MHz

RF = 5250MHz

8.0

7.7

7.3

dB

Conversion Gain Flatness

RF = 4900MHz 30MHz, LO = 5356MHz, IF = 456 30MHz

0.15

dB

Conversion Gain vs Temperature

T = –40°C to 105°C, RF = 4900MHz

C

–0.005

dB/°C

rd

2-Tone Input 3 Order Intercept

RF = 4500MHz

RF = 4900MHz

RF = 5250MHz

24.2

25.1

24.0

(∆f = 2MHz)

dBm

nd

2-Tone Input 2 Order Intercept

f

= 4779MHz, f = 5020MHz,

39.8

RF1

RF2

(∆f = 241MHz, f = f – f

)

= 5140MHz

LO

IM2

RF2

RF1

SSB Noise Figure

RF = 4500MHz

RF = 4900MHz

RF = 5250MHz

10.7

11.0

11.7

dB

dBc

2LO – 2RF Output Spurious Product

(f = f – f

f = 5020MHz at –10dBm, f = 5140MHz

RF

f = 240MHz

IF

–55

LO

)

IF/2

RF

LO

3LO – 3RF Output Spurious Product

(f = f – f

f

RF

f

IF

= 5060MHz at –10dBm, f = 5140MHz

–75

dBc

LO

)

IF/3

= 240MHz

RF

LO

Input 1dB Compression

RF = 4900MHz, V

= 3.3V

= 5V

11.3

14.5

dBm

CCIF

5544f

3

LTC5544

Dc elecTrical characTerisTics ^V_CC= 3.3V, V_CCIF= 3.3V, SHDN = Low, T_C= 25°C, unless otherwise

noted. Test circuit shown in Figure 1. (Note 2)

PARAMETER

Power Supply Requirements (V , V

CONDITIONS

MIN

TYP

MAX

UNITS

)

CC CCIF

V

Supply Voltage (Pins 5 and 7)

3.1

3.3

3.5

5.3

V

CC

Supply Voltage (Pins 14 and 15)

CCIF

V

Supply Current (Pins 5 + 7)

96

98

194

116

122

238

CC

Supply Current (Pins 14 + 15)

CCIF

mA

µA

Total Supply Current (V + V

)

CC

CCIF

Total Supply Current – Shutdown

SHDN = High

500

Shutdown Logic Input (SHDN) Low = On, High = Off

SHDN Input High Voltage (Off)

3.0

V

SHDN Input Low Voltage (On)

0.3

30

SHDN Input Current

Turn On Time

–0.3V to V + 0.3V

–20

µA

µs

CC

0.6

Turn Off Time

Temperature Sensing Diode (TEMP)

DC Voltage at T = 25°C

I

IN

I

IN

= 10µA

= 80µA

726.1

782.5

mV

J

Voltage Temperature Coefficient

I

IN

I

IN

= 10µA

= 80µA

–1.73

–1.53

mV/°C

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 3: SSB Noise Figure measurements performed with a small-signal

noise source, bandpass filter and 6dB matching pad on RF input, 6dB

matching pad on the LO input, bandpass filter on the IF output and no

other RF signals applied.

Note 2: The LTC5544 is guaranteed functional over the –40°C to 105°C

case temperature range.

Typical Dc perForMance characTerisTics ^{SHDN = Low, Test circuit shown in Figure 1.}

V_CCSupply Current vs Supply

Voltage (Mixer and LO Buffer)

V_CCIFSupply Current

Total Supply Current

vs Supply Voltage (IF Amplifier)

vs Temperature (V_CC+ V_CCIF)

102

100

135

125

220

210

200

190

180

170

T

= 105°C

= 85°C

C

T

= 85°C

C

V

CC

= 3.3V, V

= 5V

CCIF

C

(DUAL SUPPLY)

98

96

94

115

105

95

T

= 105°C

= –40°C

C

V

= V

= 3.3V

CCIF

T

= 25°C

CC

C

T

C

= 25°C

(SINGLE SUPPLY)

C

92

90

85

75

T

C

= –40°C

60 80

CASE TEMPERATURE (°C)

120

100

3.0 3.3 3.6 3.9 4.2 4.5 4.8 5.1 5.4

SUPPLY VOLTAGE (V)

–40 –20

0

20 40

3.0

3.1

3.2

3.3

3.4

3.5

3.6

V

CCIF

V

CC

SUPPLY VOLTAGE (V)

5544 G02

5544 G03

5544 G01

5544f

4

LTC5544

Typical ac perForMance characTerisTics ^{Low Side LO}

V

_CC= 3.3V, V_CCIF= 3.3V, SHDN = Low, T_C= 25°C, P_LO= 2dBm, P_RF= –3dBm (–3dBm/tone for two-tone IIP3 tests, ∆f = 2MHz),

IF = 240MHz, unless otherwise noted. Test circuit shown in Figure 1.

Conversion Gain and IIP3

vs RF Frequency

Conversion Gain and IIP3

vs RF Frequency

15

13

11

9

27

25

23

IIP3

13

11

9

25

23

V

CC

= V

V

CCIF

P

LO

P

LO

P

LO

= –1dBm

= 2dBm

= 5dBm

= 3.1V

CC

V

= 3.3V

= 3.5V

21

19

17

G

C

21

19

17

G

C

7

5

4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

RF FREQUENCY (GHz)

5544 G04

5544 G05

Conversion Gain and IIP3

vs RF Frequency

Input P1dB vs RF Frequency

15

13

11

9

16

27

15

14

13

12

11

10

9

IIP3

25

23

V

= 5V

CCIF

T = –40°C

C

T = 25°C

C

T = 85°C

C

T = 105°C

C

21

19

17

G

C

V

= 3.3V

CCIF

7

P

LO

P

LO

P

LO

= –1dBm

= 2dBm

= 5dBm

5

4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

RF FREQUENCY (GHz)

5544 G07

5544 G06

SSB NF and DSB NF

vs RF Frequency

5250MHz Conversion Gain,

IIP3 and NF vs LO Power

16

28

26

24

22

20

18

16

14

12

10

8

22

IIP3

SSB NF

20

18

16

14

12

10

8

14

12

10

8

DSB NF

NF

6

T

= –40°C

= 25°C

= 85°C

C

T

6

C

4

T

= –40°C

= 25°C

= 85°C

= 105°C

C

T

C

T

4

C

G

2

C

T

C

2

T

C

0

6

0

4.6 4.8 5.0 5.2 5.4

6.0

5.6 5.8

4.2 4.4

–3

–1

0

1

2

3

4

5

6

7

–2

LO INPUT POWER (dBm)

RF FREQUENCY (GHz)

5544 G09

5544 G08

5544f

5

LTC5544

Typical ac perForMance characTerisTics ^{Low Side LO (continued)}

V_CC= 3.3V, V_CCIF= 3.3V, SHDN = Low, T_C= 25°C, P_LO= 2dBm, P_RF= –3dBm (–3dBm/tone for two-tone IIP3 tests, ∆f = 2MHz),

IF = 240MHz, unless otherwise noted. Test circuit shown in Figure 1.

Conversion Gain, IIP3 and RF Input

P1dB vs Temperature

Single-Tone IF Output Power, 2 × 2

and 3 × 3 Spurs vs RF Input Power

2 × 2 and 3 × 3 Spurs

vs LO Power

28

26

24

22

20

18

16

14

12

10

8

20

10

–40

–50

–60

–70

–80

IIP3

IF

OUT

(RF = 5250MHz)

RF = 5250MHz

P

= –10dBm

RF

0

2RF – 2LO

(RF = 5130MHz)

RF = 5250MHz

LO = 5010MHz

V

CCIF

V

CCIF

= 5V

= 3.3V

–10

–20

–30

–40

–50

–60

–70

–80

P1dB

2RF – 2LO

(RF = 5130MHz)

3RF – 3LO

(RF = 5090MHz)

3RF – 3LO

(RF = 5090MHz)

G

C

6

–45

–5 15 35 55 75 95 115

–25

–12 –9 –6 –3

0

3

6

9

12 15

–6

–4

–2

0

2

4

6

CASE TEMPERATURE (°C)

RF INPUT POWER (dBm)

5544 G10

5544 G11

LO INPUT POWER (dBm)

5544 G12

SSB Noise Figure

vs RF Blocker Level

RF/LO Isolation

LO to RF Leakage vs LO Frequency

0

–10

–20

–30

–40

–50

60

50

40

30

20

19

18

17

16

15

14

13

12

RF = 5250MHz

LO = 5010MHz

BLOCKER = 4910MHz

P

= –1dBm

LO

C2 = OPEN

RF TO LO

P

= 2dBm

LO

RF TO IF

LO TO IF

C2 = 0.4pF

P

= 5dBm

0

C2 = 0.6pF

C2 = 1pF

LO

11

10

4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8

4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

–25

–20

–15

–10

–5

5

LO FREQUENCY (GHz)

RF/LO FREQUENCY (GHz)

RF BLOCKER POWER (dBm)

5544 G14

5544 G15

5544 G13

5250MHz Conversion Gain

Histogram

5250MHz IIP3 Histogram

5250MHz SSB NF Histogram

45

40

35

30

25

20

15

10

5

45

40

35

30

25

20

15

10

5

25

20

15

10

5

T = 85°C

T

C

= 85°C

= 25°C

= –40°C

RF = 5250MHz

RF=5250MHz

C

T

= 85°C

= 25°C

= –40°C

RF = 5250MHz

C

T = 25°C

C

T

C

T =–40°C

C

T

C

0

9.9 10.3 10.7 11.1 11.5 11.9 12.3 12.7

6.8 6.9 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9

CONVERSION GAIN (dB)

23.7 24.1 24.5 24.9 25.3 25.7 26.1 26.5 26.9

IIP3 (dBm)

SSB NOISE FIGURE (dB)

5544 G18

5544 G16

5544 G17

5544f

6

LTC5544

Typical ac perForMance characTerisTics ^{High Side LO}

V_CC= 3.3V, V_CCIF= 3.3V, SHDN = Low, T_C= 25°C, P_LO= 2dBm, P_RF= –3dBm (–3dBm/tone for two-tone IIP3 tests, ∆f = 2MHz),

IF = 240MHz, unless otherwise noted. Test circuit shown in Figure 1.

Conversion Gain and IIP3

vs RF Frequency

Conversion Gain and IIP3

vs RF Frequency

15

13

11

9

15

13

11

9

26

24

22

26

24

22

IIP3

20

18

16

20

18

16

G

C

G

C

V

CC

= V

V

CCIF

7

P

LO

P

LO

P

LO

= –1dBm

= 2dBm

= 5dBm

= 3.1V

CC

V

= 3.3V

= 3.5V

V

5

4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8

RF FREQUENCY (GHz)

5544 G19

5544 G20

Conversion Gain and IIP3

vs RF Frequency

Input P1dB vs RF Frequency

16

15

14

13

12

11

10

9

15

26

24

22

IIP3

V

CCIF

= 5V

13

11

9

T = –40°C

C

T = 25°C

C

V

CCIF

= 3.3V

20

18

16

T = 85°C

C

G

C

T = 105°C

C

7

P

LO

P

LO

P

LO

= –1dBm

= 2dBm

= 5dBm

5

4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8

RF FREQUENCY (GHz)

5544 G22

RF FREQUENCY (GHz)

5544 G21

SSB NF and DSB NF

vs RF Frequency

5250MHz Conversion Gain,

IIP3 and NF vs LO Power

16

25

23

21

19

17

15

13

11

9

20

18

16

14

12

10

8

SSB NF

14

12

10

8

IIP3

NF

DSB NF

T = –40°C

6

C

T = 25°C

C

6

T = 85°C

C

4

T = –40°C

C

4

T = 25°C

C

G

C

2

T = 85°C

C

7

2

T = 105°C

C

5

0

4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

–3

–1

0

1

2

3

4

5

6

7

–2

RF FREQUENCY (GHz)

LO INPUT POWER (dBm)

5544 G23

5544 G24

5544f

7

LTC5544

pin FuncTions

GND (Pins 1, 8, 9, 11, Exposed Pad Pin 17): Ground.

These pins must be soldered to the RF ground plane on

the circuit board. The exposed pad metal of the package

providesbothelectricalcontacttogroundandgoodthermal

contact to the printed circuit board.

nected and must be externally connected to a regulated

3.3V supply, with bypass capacitors located close to the

pins. Typical current consumption is 96mA.

LOBIAS (Pin 6): This Pin Allows Adjustment of the LO

Buffer Current. Typical DC voltage is 2.2V.

RF (Pin 2): Single-Ended Input for the RF Signal. This pin

is internally connected to the primary side of the RF input

transformer, which has low DC resistance to ground. A

series DC-blocking capacitor should be used to avoid

damage to the integrated transformer when DC voltage

is present at the RF input. The RF input is impedance

matched, as long as the LO input is driven with a 2dBm

5dB source between 4.2GHz and 5.8GHz.

LO (Pin 10): Single-Ended Input for the Local Oscillator.

This pin is internally connected to the primary side of the

RF input transformer, which has low DC resistance to

ground. A series DC blocking capacitor must be used to

avoiddamagetotheintegratedtransformerifDCvoltage

is present at the LO input.

TEMP (Pin 12): Temperature Sensing Diode. This pin is

connected to the anode of a diode that may be used to

measure the die temperature, by forcing a current and

measuring the voltage.

CT (Pin 3): RF Transformer Secondary Center-Tap. This

pin may require a bypass capacitor to ground. See the

ApplicationsInformationsection.Thispinhasaninternally

generated bias voltage of 1.2V. It must be DC-isolated

IFGND (Pin 13): DC Ground Return for the IF Amplifier.

This pin must be connected to ground to complete the IF

amplifier’s DC current path. Typical DC current is 98mA.

from ground and V .

CC

SHDN (Pin 4): Shutdown Pin. When the input voltage is

less than 0.3V, the IC is enabled. When the input voltage

is greater than 3V, the IC is disabled. Typical SHDN pin

input current is less than 10μA. This pin must not be

allowed to float.

–

+

IF (Pin 14) and IF (Pin 15): Open-Collector Differential

OutputsfortheIFAmplifier.Thesepinsmustbeconnected

to a DC supply through impedance matching inductors, or

atransformercenter-tap.TypicalDCcurrentconsumption

is 49mA into each pin.

V

(Pin 5) and V

(Pin 7): Power Supply Pins for the

CC2

CC1

IFBIAS (Pin 16): This Pin Allows Adjustment of the IF

Amplifier Current. Typical DC voltage is 2.1V.

LO Buffer and Bias Circuits. These pins are internally con-

block DiagraM

16

15

14

13

IFGND

17

TEMP

+

–

12

10

IFBIAS IF

IF

EXPOSED

PAD

IF

AMP

LO

RF

2

LO

AMP

PASSIVE

MIXER

CT

3

4

SHDN

BIAS

V

LOBIAS

CC1

CC2

5

7

6

5544 BD

GND PINS ARE NOT SHOWN

5544f

8

LTC5544

TesT circuiT

IF

OUT

4:1

240MHz

50Ω

T1

C5

L2

L1

V

CCIF

3.1V TO 5.3V

C8

C4

16

IFBIAS

GND

15

14

13

+

–

IF

IFGND

TEMP

1

2

12

11

LTC5544

C1

RF

50Ω

IN

RF

GND

L4

17

GND

C3

LO

50Ω

IN

10

9

LO

CT

3

4

C2

SHDN

(0V/3.3V)

SHDN

GND

V

LOBIAS

6

GND

8

CC1

CC2

7

5

V

CC

5544 F01

3.1V TO 3.5V

C6

C7

RF

0.015”

0.062”

0.015”

GND DC1885A

BOARD

BIAS

STACK-UP

(NELCO N4000-13)

GND

L1, L2 vs IF

Frequencies

REF DES

C1

VALUE

0.6pF

Open

SIZE

COMMENTS

0402

AVX ACCU-P

IF (MHz)

L1, L2 (nH)

C2

140

190

240

305

380

456

220

150

82

C3

1.2pF

22pF

0402

0603

AVX ACCU-P

C4, C6

C5

AVX

1000pF

1µF

56

C7, C8

L1, L2

AVX

39

150nH

Coilcraft 0603CS

L4

T1

2.2nH

0402

Coilcraft 0402HP

Mini-Circuits

TC4-1W-7ALN+

Note: For IF = 250MHz to 500MHz, use TC4-1W-17LN+ for T1

Figure 1. Standard Downmixer Test Circuit Schematic (240MHz IF)

5544f

9

LTC5544

applicaTions inForMaTion

Introduction

For the RF input to be matched, the LO input must

be driven. A broadband input match is realized with

C1 = 0.6pF and L4 = 2.2nH. The measured RF input return

loss is shown in Figure 4 for LO frequencies of 4.4GHz,

5GHz and 5.6GHz. These LO frequencies correspond to

the lower, middle and upper values of the LO range. As

shown in Figure 4, the RF input impedance is somewhat

dependent on LO frequency.

The LTC5544 consists of a high linearity passive double-

balanced mixer core, IF buffer amplifier, LO buffer ampli-

fier and bias/shutdown circuits. See the Block Diagram

section for a description of each pin function. The RF and

LO inputs are single-ended. The IF output is differential.

Low side or high side LO injection can be used. The

evaluation circuit, shown in Figure 1, utilizes bandpass IF

output matching and an IF transformer to realize a 50Ω

single-ended IF output. The evaluation board layout is

shown in Figure 2.

The RF input impedance and input reflection coefficient,

versus RF frequency, is listed in Table 1. The reference

plane for this data is Pin 2 of the IC, with no external

matching, and the LO is driven at 5GHz.

LTC5544

TO MIXER

C1

RF

IN

RF

CT

2

3

L4

C2

5544 F02

5544 F03

Figure 2. Evaluation Board Layout

Figure 3. RF Input Schematic

RF Input

0

5

The mixer’s RF input, shown in Figure 3, is connected to

the primary winding of an integrated transformer. A 50Ω

match is realized with a series capacitor (C1) and a shunt

inductor (L4). The primary side of the RF transformer

is DC-grounded internally and the DC resistance of the

primary is approximately 2.4Ω. A DC blocking capacitor

is needed if the RF source has DC voltage present.

10

15

20

25

30

35

LO = 4.4GHz

LO = 5.6GHz

LO = 5GHz

The secondary winding of the RF transformer is internally

connected to the passive mixer. The center-tap of the

transformer secondary is connected to Pin 3 (CT) to allow

the connection of bypass capacitor, C2. The value of C2 is

LO frequency-dependent and can be tuned for better LO

leakage performance. When used, C2 should be located

within2mmofPin3forproperhighfrequencydecoupling.

The nominal DC voltage on the CT pin is 1.2V.

4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

RF FREQUENCY (GHz)

5544 F04

Figure 4. RF Input Return Loss

5544f

10

LTC5544

applicaTions inForMaTion

Table 1. RF Input Impedance and S11

(at Pin 2, No External Matching, LO Input Driven at 5GHz)

low), the internal bias circuit provides a regulated 4mA

current to the amplifier’s bias input, which in turn causes

the amplifiers to draw approximately 90mA of DC current.

This 4mA reference current is also connected to LOBIAS

(Pin 6) to allow modification of the amplifier’s DC bias

current for special applications. The recommended ap-

plicationcircuitsrequirenoLOamplifierbiasmodification,

so this pin should be left open-circuited.

S11

FREQUENCY

(GHz)

INPUT

IMPEDANCE

MAG

0.44

0.41

0.40

0.38

0.31

0.21

0.25

0.29

0.28

0.25

0.26

ANGLE

34.8

31.2

29

4.0

4.2

4.4

4.6

4.8

5.0

5.2

5.4

5.6

5.8

6.0

85.8 + j54.1

89.2 + j45.6

90.9 + j41.3

95.9 + j33.6

91.4 + j17.1

72.9 + j10.7

66.7 + j24.1

70.8 + j29.1

73.1 + j26.2

69.2 + j23.9

67.3 + j25.7

23.2

15.6

20.1

43.6

40.9

36.6

39.9

43.7

The nominal LO input level is +2dBm although the limiting

amplifiers will deliver excellent performance over a 3dB

input power range. LO input power greater than +5dBm

may be used with slightly degraded performance.

The LO input impedance and input reflection coefficient,

versus frequency, is shown in Table 2.

Table 2. LO Input Impedance vs Frequency

(at Pin 10, No External Matching)

LO Input

S11

FREQUENCY

(GHz)

INPUT

IMPEDANCE

The mixer’s LO input circuit, shown in Figure 5, consists

ofabaluntransformerandatwo-stagehighspeedlimiting

differentialamplifiertodrivethemixercore.TheLTC5544’s

LO amplifiers are optimized for the 4.2GHz to 5.8GHz

LO frequency range. LO frequencies above or below this

frequencyrangemaybeusedwithdegradedperformance.

MAG

0.42

0.41

0.39

0.35

0.30

0.24

0.16

0.09

0.04

0.03

0.09

ANGLE

140.2

129.9

118.1

106.7

95

4.0

4.2

4.4

4.6

4.8

5.0

5.2

5.4

5.6

5.8

6.0

22.7 + j14.7

24.4 + j18.6

28.2 + j22.5

33.2 + j25.3

39.7 + j26.4

47.4 + j24.3

52.2 + j16.9

52 + j9.4

82.1

The mixer’s LO input is directly connected to the primary

winding of an integrated transformer. A 50Ω match is

realized with a series 1.2pF capacitor (C3). Measured LO

input return loss is shown in Figure 6.

73.3

72.7

49.9 + j3.8

47.7 – j1

88.8

–156.5

–129.4

The LO amplifiers are powered through V

(Pin 5 and Pin 7). When the chip is enabled (SHDN =

and V

CC2

CC1

44.2 – j6.2

0

5

LTC5544

LO BUFFER

C3 LO

IN

LO

10

TO

10

15

20

25

30

MIXER

4mA

BIAS

4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0

LOBIAS

V

CC2

CC1

LO FREQUENCY (GHz)

5544 F06

6

5

7

5544 F05

Figure 5. LO Input Schematic

Figure 6. LO Input Return Loss

5544f

11

LTC5544

applicaTions inForMaTion

IF Output

transformation. ItisalsopossibletoeliminatetheIFtrans-

former and drive differential filters or amplifiers directly.

The IF amplifier, shown in Figure 7, has differential

+

–

The IF output impedance can be modeled as 332Ω in

parallel with 1.7pF at IF frequencies. An equivalent small-

signal model is shown in Figure 8. Frequency-dependent

differential IF output impedance is listed in Table 3. This

data is referenced to the package pins (with no external

components) and includes the effects of IC and package

parasitics.

open-collector outputs (IF and IF ), a DC ground return

pin (IFGND), and a pin for modifying the internal bias

(IFBIAS). The IF outputs must be biased at the supply

voltage (V ), which is applied through matching induc-

CCIF

tors L1 and L2. Alternatively, the IF outputs can be biased

through the center tap of a transformer. The common

node of L1 and L2 can be connected to the center tap of

the transformer. Each IF output pin draws approximately

49mA of DC supply current (98mA total). IFGND (Pin 13)

mustbegroundedortheamplifierwillnotdrawDCcurrent.

For the highest conversion gain, high-Q wire-wound chip

inductorsarerecommendedforL1andL2,especiallywhen

15

14

+

–

IF

LTC5544

R

C

IF

usingV

=3.3V.Lowcostmultilayerchipinductorsmay

CCIF

be substituted, with a slight degradation in performance.

Grounding through inductor L3 may improve LO-IF and

RF-IF leakage performance in some applications, but is

otherwise not necessary. High DC resistance in L3 will

reduce the IF amplifier supply current, which will degrade

RF performance.

5544 F08

Figure 8. IF Output Small-Signal Model

Table 3. IF Output Impedance vs Frequency

DIFFERENTIAL OUTPUT

IMPEDANCE (R || X (C ))

FREQUENCY (MHz)

T1

IF

IF IF

IF

OUT

4:1

C10

L2

90

351 || –j707 (2.5pF)

341 || –j494 (2.3pF)

334 || –j441 (1.9pF)

332 || –j390 (1.7pF)

325 || –j312 (1.7pF)

318 || –j246 (1.7pF)

304 || –j205 (1.7pF)

R1

140

190

240

300

380

456

L1

(OPTION TO

REDUCE

DC POWER)

L3

V

+

CCIF

98mA

(OR SHORT)

C8

16

IFBIAS

15

IF

14

13

IFGND

LTC5544

–

IF

V

CC

IF

AMP

Transformer-Based Bandpass IF Matching

4mA

BIAS

The IF output can be matched for IF frequencies as low

as 40MHz, or as high as 500MHz, using the bandpass IF

matching shown in Figures 1 and 7. L1 and L2 resonate

with the internal IF output capacitance at the desired IF

frequency. The value of L1, L2 is calculated as follows:

5544 F07

Figure 7. IF Amplifier Schematic with

Transformer-Based Bandpass Match

2

L1, L2 = 1/[(2 π f ) • 2 • C ]

IF

Foroptimumsingle-endedperformance,thedifferentialIF

outputs must be combined through an external IF trans-

former or discrete IF balun circuit. The evaluation board

(see Figures 1 and 2) uses a 4:1 ratio IF transformer for

impedancetransformationanddifferentialtosingle-ended

where C is the internal IF capacitance (listed in Table 3).

IF

Values of L1 and L2 are tabulated in Figure 1 for various

IF frequencies

5544f

12

LTC5544

applicaTions inForMaTion

Discrete IF Balun Matching

Table 4. Performance Comparison with V_CCIF= 3.3V and 5V

(RF = 5250MHz, Low Side LO, IF = 240MHz)

For many applications, it is possible to replace the IF

transformer with the discrete IF balun shown in Figure 9.

The values of L5, L6, C13 and C14 are calculated to realize

a 180° phase shift at the desired IF frequency and provide

a50Ωsingle-endedoutput,usingthefollowingequations.

Inductor L7 is used to cancel the internal capacitance

V

I

G

C

P1dB

IIP3

NF

CCIF

(V)

3.3

5.0

(mA)

(dB)

(dBm)

(dB)

98

7.4

11.4

14.6

25.9

26.5

11.3

11.4

101

7.4

IF

OUT

L5

V

C15

R1

C and supplies bias voltage to the IF pin. C15 is a DC

IF

(OPTION TO

REDUCE

DC POWER)

C14

L3

(OR SHORT)

L6

L7

blocking capacitor.

98mA

CCIF

C13

R_IF• R_OUT

16

IFBIAS

15

IF

14

IF

13

–

L5,L6=

LTC5544

+

IFGND

ω_IF

1

C13, C14=

ω_IF• R_IF• R_OUT

V

CC

IF

AMP

|X_IF|

L7=

4mA

BIAS

ω_IF

5544 F09

Theseequationsgiveagoodstartingpoint, butitisusually

necessary to adjust the component values after building

and testing the circuit. The final solution can be achieved

with less iteration by considering the parasitics of L7 in

the previous calculation.

Figure 9. IF Amplifier Schematic with Discrete IF Balun

28

26

24

22

20

18

13

11

9

IIP3

The typical performances of the LTC5544 using a discrete

IF balun matching and a transformer-based IF matching

are shown in Figure 10. With an IF frequency of 456MHz,

the actual components values for the discrete balun are:

G

C

7

IF = 456MHz

LOW SIDE LO

5

TC4-1W-17LN+ BALUN

DISCRETE BALUN

L5, L6 = 36nH, L7 = 82nH and C13, C14 = 3.3pF

3

4.5 4.7 4.9 5.1 5.3 5.5 5.7 5.9 6.1 6.3

Measured IF output return losses for transformer-based

bandpass IF matching and discrete balun IF matching

(456MHz IF frequency) are plotted in Figure 11. A discrete

balun has less insertion loss than a balun transformer,

but the IF bandwidth of a discrete balun is less than that

of a transformer.

RF FREQUENCY (GHz)

5544 F10

Figure 10. Conversion Gain and IIP3 vs RF Frequency

0

L1, L2 = 150nH

L1, L2 = 82nH

L1, L2 = 39nH

5

10

15

20

25

30

DISCRETE BALUN 456MHz

IF Amplifier Bias

The IF amplifier delivers excellent performance with

V

= 3.3V, which allows the V and V

supplies

CCIF

CC

CCIF

to be common. With V

increased to 5V, the RF input

CCIF

P1dBincreasesbymorethan3dB,attheexpenseofhigher

power consumption. Mixer performance at 5250MHz is

100 150 200 250 300 350 400 450 500 550 600

shown in Table 4 with V

= 3.3V and 5V.

IF FREQUENCY (MHz)

CCIF

5544 F11

Figure 11. IF Output Return Loss

5544f

13

LTC5544

applicaTions inForMaTion

The IFBIAS pin (Pin 16) is available for reducing the DC

current consumption of the IF amplifier, at the expense of

reducedperformance.Thispinshouldbeleftopen-circuited

for optimum performance. The internal bias circuit pro-

duces a 4mA reference for the IF amplifier, which causes

the amplifier to draw approximately 98mA. If resistor R1

is connected to Pin 16 as shown in Figure 6, a portion of

the reference current can be shunted to ground, resulting

in reduced IF amplifier current. For example, R1 = 1kΩ

will shunt away 1.5mA from Pin 16 and the IF amplifier

current will be reduced by 40% to approximately 59mA.

The nominal, open-circuit DC voltage at Pin 16 is 2.1V.

Table 5 lists RF performance at 5250MHz versus IF ampli-

fier current.

LTC5544

500Ω

V

CC1

5

4

SHDN

5544 F12

Figure 12. Shutdown Input Circuit

Temperature Diode

The LTC5544 provides an on-chip diode at Pin 12 (TEMP)

forchiptemperaturemeasurement. Pin12isconnectedto

the anode of an internal ESD diode with its cathode con-

nected to internal ground. The chip temperature can be

measured by injecting a constant DC current into Pin 12

and measuring its DC voltage. The voltage vs temperature

coefficient of the diode is about –1.73mV/°C with 10µA

current injected into the TEMP pin. Figure 13 shows a

typicaltemperature-voltagebehaviorwhen10µAand80µA

currents are injected into Pin 12.

Table 5. Mixer Performance with Reduced IF Amplifier Current

(RF = 5250MHz, Low Side LO, IF = 240MHz, V_CC= V_CCIF= 3.3V)

R1

I

G

IIP3

P1dB

NF

CCIF

C

(kΩ)

(mA)

(dB)

7.4

7.2

6.9

6.3

(dBm)

(dB)

OPEN

4.7

98

25.9

25.7

25.2

23.8

11.4

11.5

11.6

11.3

11.4

11.5

11.6

89

2.2

77

1.0

59

(RF = 5250MHz, High Side LO, IF = 240MHz, V_CC= V_CCIF= 3.3V)

R1

I

G

IIP3

P1dB

NF

CCIF

C

900

(kΩ)

(mA)

(dB)

7.3

7.0

6.6

5.8

(dBm)

(dB)

850

OPEN

4.7

98

24.0

23.8

23.5

22.6

11.4

11.3

11.7

11.9

12.2

12.4

80µA

800

750

700

89

2.2

77

1.0

59

650

10µA

600

Shutdown Interface

550

500

450

400

Figure 12 shows a simplified schematic of the SHDN pin

interface. To disable the chip, the SHDN voltage must be

higher than 3.0V. If the shutdown function is not required,

the SHDN pin should be connected directly to GND. The

voltage at the SHDN pin should never exceed the power

–40 –20

0

20

40

60

80 100

JUNCTION TEMPERATURE (°C)

5544 F13

Figure 13. TEMP Diode Voltage vs Junction Temperature (T_J)

supply voltage (V ) by more than 0.3V. If this should

CC

occur, the supply current could be sourced through the

Supply Voltage Ramping

ESD diode, potentially damaging the IC.

Fast ramping of the supply voltage can cause a current

glitchintheinternalESDprotectioncircuits.Dependingon

the supply inductance, this could result in a supply volt-

age transient that exceeds the maximum rating. A supply

The SHDN pin must be pulled high or low. If left floating,

then the on/off state of the IC will be indeterminate. If a

three-state condition can exist at the SHDN pin, then a

pull-up or pull-down resistor must be used.

voltage ramp time of greater than 1ms is recommended.

5544f

14

LTC5544

package DescripTion

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

UF Package

16-Lead Plastic QFN (4mm × 4mm)

(Reference LTC DWG # 05-08-1692)

0.72 0.05

4.35 0.05

2.90 0.05

2.ꢀ5 0.05

(4 SIDES)

PACKAGE OUTLINE

0.30 0.05

0.65 BSC

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

BOTTOM VIEW—EXPOSED PAD

PIN ꢀ NOTCH R = 0.20 TYP

OR 0.35 × 45° CHAMFER

0.75 0.05

R = 0.ꢀꢀ5

TYP

4.00 0.ꢀ0

(4 SIDES)

ꢀ5

ꢀ6

0.55 0.20

PIN ꢀ

TOP MARK

(NOTE 6)

ꢀ

2

2.ꢀ5 0.ꢀ0

(4-SIDES)

(UFꢀ6) QFN ꢀ0-04

0.200 REF

0.30 0.05

0.65 BSC

0.00 – 0.05

NOTE:

ꢀ. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGC)

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.ꢀ5mm ON ANY SIDE

5. EXPOSED PAD SHALL BE SOLDER PLATED

6. SHADED AREA IS ONLY A REFERENCE FOR PIN ꢀ LOCATION

ON THE TOP AND BOTTOM OF PACKAGE

5544f

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-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

15

LTC5544

Typical applicaTion

900MHz IF Output Matching

Conversion Gain,

IIP3 and NF vs RF Frequency

TM4-1

(SYNERGY)

IF

OUT

50Ω

30

28

26

24

22

20

18

16

14

12

10

9

8

7

6

5

4

3

2

1

0

3.3pF

IIP3

1000pF

22nH

1000pF

IF = 900MHz

LOW SIDE LO

22nH

V

3.3V

CCIF

1µF

22pF

+

–

IF

IFGND TEMP

G

C

IF

0.6pF

1.2pF

RF

IN

LO

IN

50Ω

LO

50Ω

RF

SSB NF

2.2nH

SHDN

4.9 5.1 5.3 5.5 5.7 5.9 6.1 6.3

SHDN

RF FREQUENCY (GHz)

BIAS

5544 TA02b

V

CC1

V

CC2

5544 TA02a

V

3.3V

CC

1µF

22pF

relaTeD parTs

PART NUMBER DESCRIPTION

COMMENTS

Infrastructure

LTC554X

LT^®5527

LT5557

600MHz to 6GHz 3.3V Downconverting Mixers

400MHz to 3.7GHz, 5V Downconverting Mixer

8dB Gain, 26dBm IIP3, 10dB NF, 3.3V/200mA Supply

2.3dB Gain, 23.5dBm IIP3 and 12.5dB NF at 1900MHz, 5V/78mA Supply

2.9dB Gain, 24.7dBm IIP3 and 11.7dB NF at 1950MHz, 3.3V/82mA Supply

400MHz to 3.8GHz, 3.3V Downconverting Mixer

LTC559x

LTC5569

LTC6400-X

LTC6416

LTC6412

LT5554

600MHz to 4.5GHz Dual Downconverting Mixer Family 8.5dB Gain, 26.5dBm IIP3, 9.9dB NF, 3.3V/380mA Supply

300MHz to 4GHz 3.3V Dual Downconverting Mixer

300MHz Low Distortion IF Amp/ADC Driver

2GHz 16-Bit ADC Buffer

2dB Gain, 26.8dBm IIP3 and 11.7dB NF at 1950MHz, 3.3V/180mA Supply

Fixed Gain of 8dB, 14dB, 20dB and 26dB; >36dBm OIP3 at 300MHz, Differential I/O

40dBm OIP3 to 300MHz, Programmable Fast Recovery Output Clamping

35dBm OIP3 at 240MHz, Continuous Variable Gain Range –14dB to 17dB

48dBm OIP3 at 200MHz, 2dB to 18dB Gain Range, 0.125dB Gain Steps

27dBm OIP3 at 900MHz, 24.2dBm at 1.95GHz, Integrated RF Transformer

27.3dBm OIP3 at 2.14GHz, NF = 9.9dB, 3.3V Supply, Single-Ended LO and RF Ports

31dBm OIP3 at 2.14GHz, –160.6dBm/Hz Noise Floor

31dB Linear Analog VGA

Ultralow Distort IF Digital VGA

LT5578

400MHz to 2.7GHz Upconverting Mixer

1.5GHz to 3.8GHz Upconverting Mixer

200MHz to 6GHz I/Q Modulator

LT5579

LTC5588-1

RF Power Detectors

LTC5587

LT5581

6GHz RMS Detector with 12-Bit ADC

40dB Dynamic Range, 1dB Accuracy Over Temperature, 3mA Current, 500ksps

40dB Dynamic Range, 1dB Accuracy Over Temperature, 1.5mA Supply Current

57dB Dynamic Range, 0.5dB Accuracy Over Temperature, 0.2dB Linearity Error

Up to 60dB Dynamic Range, 0.5dB Accuracy Over Temperature, >50dB Isolation

6GHz Low Power RMS Detector

40MHz to 10GHz RMS Detector

Dual 6GHz RMS Power Detector

LTC5582

LTC5583

ADCs

LTC2208

LTC2285

LTC2268-14

16-Bit, 130Msps ADC

78dBFS Noise Floor, >83dB SFDR at 250MHz

Dual 14-Bit, 125Msps Low Power ADC

Dual 14-Bit, 125Msps Serial Output ADC

72.4dB SNR, 88dB SFDR, 790mW Power Consumption

73.1dB SNR, 88dB SFDR, 299mW Power Consumption

5544f

LT 0312 • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

16

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 LINEAR TECHNOLOGY CORPORATION 2012

(408) 432-1900 FAX: (408) 434-0507 www.linear.com


型号：	LTC5544
厂家：	Linear
描述：	4GHz to 6GHz High Dynamic Range Downconverting Mixer 4GHz的6GHz的高动态范围下变频混频器
文件：	总16页 (文件大小：360K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LTC5544 [Linear]

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