1.7GHz to 2.5GHz, Direct I/Q Modulator with VGA and PA Driver · CDMA and wireless local-loop (WLL) systems. Their direct-upconversion architecture reduces system cost, component

General DescriptionThe MAX2720/MAX2721 are low-cost, high-performance,direct I/Q modulators designed for use in wideband-CDMA and wireless local-loop (WLL) systems. Theirdirect-upconversion architecture reduces system cost,component count, and board space compared todevices with dual-conversion architectures.

The MAX2720/MAX2721 include an I/Q modulator, avariable gain amplifier (VGA), and a power amplifier(PA) driver. The quadrature modulator accepts differentialbaseband I/Q signals and directly modulates an RFcarrier in the 1.7GHz to 2.1GHz range (MAX2720) orthe 2.1GHz to 2.5GHz range (MAX2721). The VGA pro-vides 35dB of output power control. The modulator’samplitude and phase balance yield 35dBc of sidebandsuppression and 30dBc of carrier suppression. Thesedevices feature an LO frequency doubler that allowsthe external LO source to operate at half-frequency orfull-frequency when disabled.

The MAX2720/MAX2721 operate from a single +2.7V to+3.3V supply and require only 77mA (MAX2720) or86mA (MAX2721) of supply current. An additional20mA of supply current is saved by disabling thestand-alone PA driver. A low-power shutdown modefurther reduces supply current to less than 0.1µA. Thedevice is packaged in the small 20-pin TSSOP-EP withexposed paddle to improve RF performance.

ApplicationsWireless Local Loop (WLL)

Wideband CDMA Systems

LMDS/MMDS

2.4GHz Broadband ISM Radios

DCS/PCS Base Stations

Features RF Frequency Range

1.7GHz to 2.1GHz (MAX2720)2.1GHz to 2.5GHz (MAX2721)

Integrated I/Q Modulator, LO Doubler, VGA, andPA Driver

35dB VGA Gain Control Range

35dBc Sideband Suppression

30dBc Carrier Suppression

Low Supply Current77mA (MAX2720), 86mA (MAX2721)20mA Reduction with PA Driver Disabled

0.1µA Supply Current in Shutdown Mode

+2.7V to +3.3V Single-Supply Operation

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1.7GHz to 2.5GHz, Direct I/Q Modulator withVGA and PA Driver

________________________________________________________________ Maxim Integrated Products 1

4

5

20 DRIN

19 GND

18 PC

VCC

2DROUT

1GND

17 MODOUT

16

15 VCC

14 Q-7I-

6VCC

GND

13 Q+

12 VCC

11 LO

9VCC

8I+

MAX2720/MAX2721

3SHDN

ENX2

0°90°

PA DRIVER

VGA

LO DOUBLER

LO P

HASE

SHI

FTER

10GND

Σ

x2BIAS

Functional Diagram

19-1606; Rev 0; 1/00

PART

MAX2720EUP

MAX2721EUP -40°C to +85°C

-40°C to +85°C

TEMP. RANGE PIN-PACKAGE

20 TSSOP-EP*

20 TSSOP-EP*

Pin Configuration appears at end of data sheet.

*Exposed paddle.

Ordering Information

For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.

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1.7GHz to 2.5GHz, Direct I/Q Modulator with VGA and PA Driver

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS(VCC = +2.7V to +3.3V; SHDN = VCC; ENX2 = GND; VPC = 0.5V; no input AC signals applied to I+, I-, Q+, Q-, LO, DRIN. MODOUTand DROUT = VCC, TA = -40°C to +85°C. Typical values are at VCC. = +3V, TA = +25°C, unless otherwise noted.)

AC ELECTRICAL CHARACTERISTICS(MAX2720/MAX2721 EV Kit, VCC = +3.0V, SHDN = VCC, ENX2 = GND, VPC = 2.5V, input I/Q signals driven in quadrature, from a1kΩ source impedance, single-ended, fI+ = fQ+ = 500kHz, VI+ = VQ+ = 200mVp-p, PLO = -13dBm, fLO = 950MHz (MAX2720), fLO =1157.5MHz (MAX2721), PDRIN = -12dBm, fDRIN = 1900MHz (MAX2720), fDRIN = 2315MHz (MAX2721), MODOUT and DROUT portsare matched to a 50Ω load, TA = +25°C, unless otherwise noted.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functionaloperation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure toabsolute maximum rating conditions for extended periods may affect device reliability.

VCC to GND..............................................................-0.3V to +6VENX2, SHDN, PC, I+, I-, Q+, Q-, LO,

DRIN to GND........................................-0.3V to (VCC + 0.3V)ENX2, SHDN Continuous Current.....................................±10mAPC Continuous Current.....................................................±10mAI+ to I-, Q+ to Q- ....................................................................±2VMODOUT, DROUT to GND Short-Circuit Duration .................10s

Continuous Power Dissipation (TA = +70°C)20-Pin TSSOP-EP (derate 21.7mW/°C above +70°C) ......1.74W

Operating Temperature Range ...........................-40°C to +85°CJunction Temperature ......................................................+150°CStorage Temperature Range ............................ -65°C to +150°CLead Temperature (soldering 10s) ................................. +300°C

MAX2721

MAX2720

0.5V < VPC < 2.5V, SHDN = GND

0.5V < VPC < 2.5V

MAX2720, DRIN = GND

MAX2721, DRIN = GND

SHDN = GND

CONDITIONS

86 129mA

77 119

V2.7 3.3Supply Voltage

Supply Current

2.5µA

-5 5PC Input Bias Current

µA-1 1Logic Input Bias Current

V0.5Logic Input Low Voltage

mA59 86Supply Current with PA Driver

Disabled 67 96

µA0.1 10Shutdown Supply CurrentV2.0Logic Input High Voltage

UNITSMIN TYP MAXPARAMETER

100kHz < fI = fQ < 2MHz

100kHz < fI+ = fQ+ < 2MHz

fI = fQ < BW-1dB

fI = fQ < BW-1dB

fI = fQ < BW-3dB, 0.5V < VPC < 2.5V

fI = fQ < BW-3dB, 0.5V < VPC < 2.5V

fI = fQ < BW-1dB

CONDITIONS

MHz40I/Q Input -3dB Bandwidth (Note 2)

MHz14 20

I/Q BASEBAND INPUTS

I/Q Input -1dB Bandwidth (Note 2)

ns1Group Delay Mismatch

ns1Group Delay Ripple

pF5I/Q Input Capacitance

Ω18I/Q Input Resistance Mismatch

mVp-p200 630I/Q Differential Input Level

dB±0.2I/Q Gain Imbalance

degrees±1.0I/Q Phase Imbalance

kΩ1.6 2.0I/Q Input Resistance


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AC ELECTRICAL CHARACTERISTICS (continued)(MAX2720/MAX2721 EV Kit, VCC = +3.0V, SHDN = VCC, ENX2 = GND, VPC = 2.5V, input I/Q signals driven in quadrature, from a1kΩ source impedance, single-ended, fI+ = fQ+ = 500kHz, VI+ = VQ+ = 200mVp-p, PLO = -13dBm, fLO = 950MHz (MAX2720), fLO =1157.5MHz (MAX2721), PDRIN = -12dBm, fDRIN = 1900MHz (MAX2720), fDRIN = 2315MHz (MAX2721), MODOUT and DROUT portsare matched to a 50Ω load, TA = +25°C, unless otherwise noted.) (Note 1)

VPC = 2.5V

MAX2721

ENX2 = GND

MAX2721

MAX2720

ENX2 = VCC

VPC = 2.5V

0.5V < VPC < 2.5V

VPC = 2.5V, I/Q terminated in 50Ω

Slope between VPC = 1V and VPC = 2V

dBm+8 +14

MAX2721, VPC = 2.5V, ENX2 = VCC or GND, TA = +25°C (Note 3)

Output Third-Order Intercept Point(Note 4)

MAX2720

CONDITIONS

+3 +6

MAX2721

MAX2721

ENX2 = GND

30 40

ENX2 = VCC

20 25

ENX2 = GND

ENX2 = VCC

24 31

ENX2 = GND

ENX2 = VCC

MAX2720, 0.5V < VPC < 2.5V

+9 +14

2:1Output VSWR

dBm/Hz-141 -137Out-of-Band Noise Density

26 33

MAX2720

MAX2721

VCC = +3.0V + 100mVp-p at 10kHz/300kHz

MAX2720

0.5V < VPC < 2.5V

50 45MODOUT to LO Input Isolation

1.8:1

1.9:1

LO Input VSWR

2100 2500

MAX2720, VPC = 2.5V, ENX2 = VCC or GND, TA = +25°C (Note 3)

MHz1700 2100

2100 2500

1050 1250

1.8:1

Frequency Range (Note 3)

dBm+1 +5

Output 1dB Compression Point

dB/V19 23

dBc

PC Slope

VPC = 2.5V

41

VPC = 0.5V

Power-Supply Ripple Rejection(Note 5)

dBm

-12.5 -8.5 -6.0

Output Power, High

MAX2720

-10.5 -5.0 -2.5

MAX2721

MHz

UNITSMIN TYP MAX

850 1050

PARAMETER

LO Frequency Range (Note 3)1700 2100

28 35

1.6:1

MODULATOR OUTPUT

dBcCarrier Suppression

Sideband Suppression dBc

dB

VPC = 2.5V, TA = -40°C to +85°C

dB±1.0 ±1.8Output Power Variation Over

Temperature ±0.8 ±1.5

MAX2720

MAX2721

MAX2720

MAX2721

dBm-16 -10LO Input Power (Note 3)

VPC = 0.5V, ENX2 = VCC or GND

dB29 35

Power Control Range28 32

MAX2720

MAX2721

LO BUFFER, LO FREQUENCY DOUBLER, QUADRATURE GENERATOR

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Note 1: Min/max limits are guaranteed by design and characterization and are not production tested.Note 2: I/Q input bandwith is determined by the baseband source impedance and the I/Q input capacitance. The bandwith can be

increased by lowering the baseband source impedance.Note 3: MODOUT output power specifications are met over this frequency range for VPC = 2.5V and TA = +25°C.Note 4 IP3 measured with two tones, f1 = 500kHz and f2 = 600kHz, at 100mVp-p each.Note 5: Measured relative to desired upconverted signal level.Note 6 DROUT gain specifications are met over this frequency range at TA = +25°C.Note 7: IP3 measured with two tones, f1 = 1900MHz and f2 = 1901MHz, at -18dBm each.Note 8: IP3 measured with two tones, f1 = 2315MHz and f2 = 2316MHz, at -18dBm each.

CONDITIONS

MAX2720

MAX2721

MAX2720

MAX2721


MAX2720

MAX2720

MAX2721

MAX2720

MAX2721

TA = -40°C to +85°C

MHz1700 2100

Frequency Range (Note 6)

dBm+9.5 +12.5

Output 1dB Compression Point

2.6dB

2.4Noise Figure

±0.3 ±0.8

2100 2500

dB

11 13.5 15.5

Gain Variation Over Temperature

8.5 11.5 15.5

±0.4 ±0.8

MAX2721 (Note 8)

MAX2720 (Note 7)

MAX2721

dB19Reverse Isolation

+20 +24

dB65DROUT to LO Input Isolation

1.5:1Input VSWR

1.5:1Output VSWR

dBm+22 +24

Output Third-Order Intercept Point

+8 +11

AC ELECTRICAL CHARACTERISTICS (continued)(MAX2720/MAX2721 EV Kit, VCC = +3.0V, SHDN = VCC, ENX2 = GND, VPC = 2.5V, input I/Q signals driven in quadrature, from a1kΩ source impedance, single-ended, fI+ = fQ+ = 500kHz, VI+ = VQ+ = 200mVp-p, PLO = -13dBm, fLO = 950MHz (MAX2720), fLO =1157.5MHz (MAX2721), PDRIN = -12dBm, fDRIN = 1900MHz (MAX2720), fDRIN = 2315MHz (MAX2721), MODOUT and DROUT portsare matched to a 50Ω load, TA = +25°C, unless otherwise noted.) (Note 1)

Gain (Note 6) dB

PA DRIVER

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0

30

20

10

40

50

60

70

80

90

100

2.7 2.92.8 3.0 3.1 3.2 3.3

SUPPLY CURRENT vs. SUPPLY VOLTAGEWITH PA DRIVER ENABLED

MAX

2720

/21t

oc01

SUPPLY VOLTAGE (V)

SUPP

LY C

URRE

NT (m

A)

TA = +85°C

TA = +25°C

TA = -40°C

ENX2 = GNDENX2 = VCC 0

30

20

10

40

50

60

70

80

90

100

2.7 2.92.8 3.0 3.1 3.2 3.3

SUPPLY CURRENT vs. SUPPLY VOLTAGEWITH PA DRIVER DISABLED

MAX

2720

/21t

oc02

SUPPLY VOLTAGE (V)

SUPP

LY C

URRE

NT (m

A)

ENX2 = GNDENX2 = VCC

DRIN = GNDTA = +85°C

TA = +25°C

TA = -40°C

-60

-50

-40

-30

-20

-10

0

1700 1800 1900 2000 2100

MODULATOR OUTPUT POWERvs. RF FREQUENCY

MAX

2720

/21t

oc04

RF FREQUENCY (MHz)

OUTP

UT P

OWER

(dBm

)

TA = +85°C

VPC = 2.5V

VPC = 1.5V

VPC = 0.5V

TA = +25°C

TA = -40°C

-60

-40

-50

-20

-30

-10

0

-19 -13 -11-17 -15 -9 -7 -5

MAX

2720

/21t

oc05

LO POWER (dBm)

OUTP

UT P

OWER

(dBm

) AND

CAR

RIER

AN

D SI

DEBA

ND S

UPPR

ESSI

ON (d

Bc) OUTPUT POWER

CARRIER SUPPRESSION

SIDEBAND SUPPRESSION

MODULATOR PERFORMANCE vs. LO POWER (ENX2 = GND)

-70

-50

-60

-20

-30

-40

-10

0

-19 -13 -11-17 -15 -9 -7 -5

MAX

2720

/21t

oc06

LO POWER (dBm)

OUTP

UT P

OWER

(dBm

) AND

CAR

RIER

AN

D SI

DEBA

ND S

UPPR

ESSI

ON (d

Bc) OUTPUT POWER

MODULATOR PERFORMANCE vs. LO POWER (ENX2 = VCC)

CARRIER SUPPRESSION

SIDEBANDSUPPRESSION

Typical Operating Characteristics(MAX2720/MAX2721 EV Kit, VCC = +3.0V, SHDN = VCC, ENX2 = GND, VPC = 2.5V, input I/Q signals driven in quadrature, from a1kΩ source impedance, single-ended, fI+ = fQ+ = 500kHz, VI+ = VQ+ = 200mVp-p, PLO = -13dBm, fLO = 950MHz (MAX2720), fLO =1157.5MHz (MAX2721), PDRIN = -12dBm, fDRIN = 1900MHz (MAX2720), fDRIN = 2315MHz (MAX2721), MODOUT and DROUT portsare matched to a 50Ω load, TA = +25°C, unless otherwise noted.) (Note 1)

MAX2720

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-50

-35

-40

-45

-15

-10

-20

-30

-25

-5

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc10

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)

MODULATOR OUTPUT POWER vs. PC VOLTAGE (ENX2 = VCC)

2.1GHz

1.9GHz

1.7GHz

-70

-50

-60

-40

-10

-20

-30

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc11

PC VOLTAGE (V)

CARR

IER

SUPP

RESS

ION

(dBc

)

MODULATOR CARRIER SUPPRESSION vs. PC VOLTAGE (ENX2 = VCC)

2.1GHz

1.9GHz

1.7GHz

-50

-35

-40

-45

-15

-10

-20

-30

-25

-5

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc12

PC VOLTAGE (V)

SIDE

BAND

SUP

PRES

SION

(dBc

)

MODULATOR SIDEBAND SUPPRESSION vs. PC VOLTAGE (ENX2 = VCC)

2.1GHz

1.7GHz1.9GHz

Typical Operating Characteristics (continued)(MAX2720/MAX2721 EV Kit, VCC = +3.0V, SHDN = VCC, ENX2 = GND, VPC = 2.5V, input I/Q signals driven in quadrature, from a1kΩ source impedance, single-ended, fI+ = fQ+ = 500kHz, VI+ = VQ+ = 200mVp-p, PLO = -13dBm, fLO = 950MHz (MAX2720), fLO =1157.5MHz (MAX2721), PDRIN = -12dBm, fDRIN = 1900MHz (MAX2720), fDRIN = 2315MHz (MAX2721), MODOUT and DROUT portsare matched to a 50Ω load, TA = +25°C, unless otherwise noted.) (Note 1)

-40

-35

-15

-10

-20

-30

-25

-5

0

0 1.50.5 1.0 2.0 2.5 3.0M

AX27

20/2

1toc

08

PC VOLTAGE (V)

CARR

IER

SUPP

RESS

ION

(dBc

)MODULATOR CARRIER SUPPRESSION

vs. PC VOLTAGE (ENX2 = GND)

2.1GHz

1.9GHz

1.7GHz-60

-40

-50

-20

-30

-10

0

0 1.0 1.50.5 2.0 2.5 3.0

MAX

2720

/21t

oc09

PC VOLTAGE (V)

SIDE

BAND

SUP

PRES

SION

(dBc

)

MODULATION SIDEBAND SUPPRESSIONvs. PC VOLTAGE (ENX2 = GND)

2.1GHz

1.9GHz

1.7GHz

MAX2720

-50

-35

-40

-45

-15

-10

-20

-30

-25

-5

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc07

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)

1.9GHz

1.7GHz

2.1GHz

MODULATOR OUTPUT POWER vs. PC VOLTAGE (ENX2 = GND)

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-35

-40

-15

-10

-20

-30

-25

-5

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc14

PC VOLTAGE (V)

CARR

IER

SUPP

RESS

ION

(dBc

)

MODULATOR CARRIER SUPPRESSION vs. PC VOLTAGE (ENX2 = GND)

TA = +85°C

TA = +25°CTA = -40°C

-55

-60

-20

-30

-40

-10

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc15

PC VOLTAGE (V)

SIDE

BAND

SUP

PRES

SION

(dBc

)

MODULATOR SIDEBAND SUPPRESSION vs. PC VOLTAGE (ENX2 = GND)

TA = +85°C

TA = +25°C

TA = -40°C

-45

-40

-50

-15

-20

-25

-35

-30

-5

-10

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc16

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)


TA = +85°C

TA = +25°C

TA = -40°C

-40

-70

-50

-60

-20

-30

-10

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc17

PC VOLTAGE (V)

CARR

IER

SUPR

ESSI

ON (d

Bc)

MODULATOR CARRIER SUPPRESSION vs. PC VOLTAGE (ENX2 = VCC)

TA = +85°C

TA = +25°C

TA = -40°C

-40

-50

-60

-20

-30

-10

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc18

PC VOLTAGE (V)

SIDE

BAND

SUP

RESS

ION

(dBc

)

TA = +85°C

TA = -40°C

MODULATOR SIDEBAND SUPPRESSION vs. PC VOLTAGE (ENX2 = VCC)

TA = +25°C

MAX2720

-50

-35

-40

-45

-15

-10

-20

-30

-25

-5

0

0 1.50.5 1.0 2.0 2.5 3.0

MAX

2720

/21t

oc13

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)

TA = +85°C

TA = +25°C

TA = -40°C


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-6010 10,0001000100

MODULATOR OUTPUT POWER vs. INPUT LEVEL (TA = +25°C)

10

-30

-40

-50

0

-10

-20

MAX

2720

toc2

0INPUT LEVEL (mVp-p)

OUTP

UT P

OWER

(dBm

)

VPC = 2.5V

VPC = 2.0V

VPC = 1.5V

VPC = 1.0V

VPC = 0.5V

-6010 10,0001000100

MODULATOR OUTPUT POWER vs. INPUT LEVEL (TA = +85°C)

10

-30

-40

-50

0

-10

-20

MAX

2720

toc2

1

INPUT LEVEL (mVp-p)

OUTP

UT P

OWER

(dBm

)

VPC = 2.5V

VPC = 2.0V

VPC = 1.5V

VPC = 1.0V

VPC = 0.5V

-20

-15

-30

-25

15

10

0

-5

-10

5

20

25

1.00 0.5 1.5 2.0 2.5 3.0

MODULATOR OUTPUT IP3 vs. PC VOLTAGE

MAX

2720

/21t

oc22

PC VOLTAGE (V)

OUTP

UT IP

3 (d

Bm) TA = +25°C

TA = -40°C

TA = +85°C

1.0

1.2

1.6

2.0

2.4

2.8

850 890 930 970 1010 1050

MAX

2720

-24

FREQUENCY (MHz)

VSW

R

LO PORT VSWR vs. LO FREQUENCY (ENX2 = GND)

1.0

1.4

1.8

2.0

2.4

2.8

1700 1780 1860 1940 2020 2100

MAX

2720

-25

FREQUENCY (MHz)

VSW

R

LO PORT VSWR vs. LO FREQUENCY (ENX2 = VCC)


MAX2720

-6010 10,0001000100

MODULATOR OUTPUT POWER vs. INPUT LEVEL (TA = -40°C)

10

-30

-40

-50

0

-10

-20

MAX

2720

toc1

9

INPUT LEVEL (mVp-p)

OUTP

UT P

OWER

(dBm

)

VPC = 2.5V

VPC = 2.0V

VPC = 1.5V

VPC = 1.0V

VPC = 0.5V

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10

11

12

13

14

15

2.7 2.92.8 3.0 3.1 3.2 3.3

PA DRIVER GAIN vs. SUPPLY VOLTAGE

MAX

2720

/21t

oc27

SUPPLY VOLTAGE (V)

GAIN

(dB)

TA = +85°CTA = +25°C

TA = -40°C

20

22

21

23

24

26

25

28

27

29

30

2.7 2.92.8 3.0 3.1 3.2 3.3

PA DRIVER OUTPUT IP3 vs. SUPPLY VOLTAGE

MAX

2720

/21t

oc28

SUPPLY VOLTAGE (V)

OUTP

UT IP

3 (d

Bm) TA = +85°C

TA = +25°C

TA = -40°C

Page 1

10

12

11

13

14

16

15

18

17

19

20

2.7 2.92.8 3.0 3.1 3.2 3.3

PA DRIVER OUTPUT P1dB vs. SUPPLY VOLTAGE

MAX

2720

/21t

oc29

SUPPLY VOLTAGE (V)

OUTP

UT P

1dB

(dBm

)

TA = +85°C

TA = +25°C

TA = -40°C

0

4

2

6

8

12

10

16

14

18

20

1700 1800 1900 2000 2100

PA DRIVER GAIN vs. RF FREQUENCY

MAX

2720

/21t

oc30

RF FREQUENCY (MHz)

GAIN

(dB)

TA = +25°CTA = +85°C

TA = -40°C


20

22

21

23

24

26

25

28

27

29

30

1700 1800 1900 2000 2100

PA DRIVER OUTPUT IP3 vs. FREQUENCY

MAX

2720

/21t

oc31

FREQUENCY (MHz)

OUTP

UT IP

3 (d

Bm)

TA = +25°CTA = +85°C

TA = -40°C

10

12

11

13

14

16

15

18

17

19

20

1700 1800 1900 2000 2100

PA DRIVER OUTPUT P1dB COMPRESSION POINT vs. FREQUENCY

MAX

2720

/21t

oc32

FREQUENCY (MHz)

OUTP

UT P

1dB

(dBm

)

TA = +25°C

TA = -40°C

TA = +85°C

MAX2720

MA

X2

72

0/M

AX

27

21


10 ______________________________________________________________________________________


0

1.0

0.5

1.5

2.0

3.0

2.5

4.0

3.5

4.5

5.0

1700 1800 1900 2000 2100

PA DRIVER NOISE FIGURE vs. FREQUENCY

MAX

2720

/21t

oc33

FREQUENCY (MHz)

NOIS

E FI

GURE

(dB)

TA = +25°CTA = +85°C

TA = -40°C-15

-10

-5

10

5

0

15

20

-25 -15 -10-20 -5 50 10 2015

PA DRIVER OUTPUT POWER vs. INPUT POWER

MAX

2720

/21t

oc34

INPUT POWER (dBm)

OUTP

UT P

OWER

(dBm

)

TA = -40°C

TA = +85°C

TA = +25°C

MAX2720

MA

X2

72

0/M

AX

27

21


______________________________________________________________________________________ 11

-50

-40

-45

-30

-35

-20

-25

-15

-5

-10

0

2100 2200 2300 2400 2500

MODULATOR OUTPUT POWERvs. RF FREQUENCY

MAX

2720

toc3

8

RF FREQUENCY (MHz)

OUTP

UT P

OWER

(dBm

)

VPC = 2.5V

VPC = 1.5V

VPC = 0.5V

TA= +85°CTA= +25°C

TA= -40°C

-40

-30

-35

-25

-20

-5

-15

-10

0

-19 -17 -15 -13 -11 -9 -7 -5

MODULATOR PERFORMANCE vs. LO POWER (ENX2 = GND)

MAX

2720

/21t

oc39

RF FREQUENCY (MHz)

OUTP

UT P

OWER

(dBm

) AND

CAR

RIER

AND

SI

DEBA

ND S

UPPR

ESSI

ON (d

Bc)

OUTPUT POWER

CARRIER SUPPRESSION


-40

-30

-35

-25

-20

-15

-5

-10

0

-19 -17 -15 -13 -9 -7-11 -5

MODULATOR PERFORMANCE vs. LO POWER (ENX2 = VCC)

MAX

2720

/21t

oc40

LO POWER (dBm)

OUTP

UT P

OWER

(dBm

) AND

CAR

RIER

AND

SI

DEBA

ND S

UPPR

ESSI

ON (d

Bc)

OUTPUT POWER

CARRIER SUPPRESSION


20

30

50

40

70

60

110

100

90

80

120

2.7 2.92.8 3.0 3.1 3.2 3.3

SUPPLY CURRENT vs. SUPPLY VOLTAGEWITH PA DRIVER ENABLED

MAX

2720

/21t

oc35

SUPPLY VOLTAGE (V)

SUPP

LY C

URRE

NT (m

A)

TA = +85°C

TA = +25°C

TA = -40°C


20

40

30

60

50

100

90

80

70

120

110

2.7 2.92.8 3.0 3.1 3.2 3.3

SUPPLY CURRENT vs. SUPPLY VOLTAGEWITH PA DRIVER DISABLED

MAX

2720

/21t

oc36

SUPPLY VOLTAGE (V)

SUPP

LY C

URRE

NT (m

A)

TA = +25°C

TA = -40°C

TA = +85°C

DRIN = GND



MAX2721

MA

X2

72

0/M

AX

27

21


12 ______________________________________________________________________________________


-40

-35

-30

-25

-20

-15

-10

-5

0

0 1.00.5 1.5 2.0 2.5 3.0

MODULATOR SIDEBAND SUPRESSION vs. PC VOLTAGE (ENX2 = VCC)

MAX

2721

TOC

46

PC VOLTAGE (V)

SIDE

BAND

SUP

RESS

ION

(dBc

)

2.1GHz

2.5GHz2.3GHz

-45

-35

-40

-20

-25

-30

-5

-10

-15

0

0 1.00.5 1.5 2.0 2.5 3.0

MODULATOR OUTPUT POWERvs. PC VOLTAGE (ENX2 = VCC)

MAX

2721

TOC

44

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)

2.1GHz

2.3GHz2.5GHz

-45

-35

-40

-20

-25

-30

-5

-10

-15

0

0 1.00.5 1.5 2.0 2.5 3.0

MODULATOR CARRIER SUPRESSIONvs. PC VOLTAGE (ENX2 = VCC)

MAX

2721

TOC

45

PC VOLTAGE (V)

CARR

IER

SUPR

ESSI

ON (d

Bc)

2.1GHz

2.3GHz 2.5GHz

-40

-30

-35

-25

-20

-15

-5

-10

0

0 0.5 1.0 2.0 2.51.5 3.0

MAX

2720

/21t

oc42

PC VOLTAGE (V)

CARR

IER

SUPP

RESS

ION

(dBm

)

CARRIER SUPPRESSION vs. PC VOLTAGE(ENX2 = GND)

2.5GHz

2.1GHz

2.3GHz

-40

-35

-30

-25

-20

-15

-10

-5

0

0 1.00.5 1.5 2.0 2.5 3.0

SIDEBAND SUPRESSION vs. PC VOLTAGE(ENX2 = GND)

MAX

2721

TOC

43

PC VOLTAGE (V)

SIDE

BAND

SUP

RESS

ION

(dBc

)

2.3GHz2.1GHz

2.5GHz

MAX2721

-40

-30

-35

-25

-20

-15

-5

-10

0

0 0.5 1.0 1.5 2.0 3.02.5

MAX

2720

/21t

oc41

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)


2.3GHz

2.1GHz

2.5GHz

MA

X2

72

0/M

AX

27

21


______________________________________________________________________________________ 13


-40

-35

-30

-25

-20

-15

-10

-5

0

0 1.00.5 1.5 2.0 2.5 3.0

MODULATOR OUTPUT POWERvs. PC VOLTAGE (ENX2 = GND)

MAX

2721

TOC

47

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)

TA = +25°C

TA = -40°C

TA = +85°C

-35

-25

-30

-15

-20

-5

-10

0

0 1.0 1.50.5 2.0 2.5 3.0

MODULATOR CARRIER SUPRESSION vs. PC VOLTAGE (ENX2 = GND)

MAX

2721

TOC

48PC VOLTAGE (V)

CARR

IER

SUPR

ESSI

ON (d

Bc)

TA = +85°C

TA = +25°C

TA = -40°C

-40

-35

-30

-25

-20

-15

-10

-5

0

0 1.00.5 1.5 2.0 2.5 3.0

MODULATOR SIDEBAND SUPRESSIONvs. PC VOLTAGE (ENX2 = GND)

MAX

2721

TOC

49

PC VOLTAGE (V)

SIDE

BAND

SUP

RESS

ION

(dBc

)

TA = -40°CTA = +25°C

TA = +85°C

-40

-35

-30

-25

-20

-15

-10

-5

0

0 1.00.5 1.5 2.0 2.5 3.0


MAX

2721

TOC

450

PC VOLTAGE (V)

OUTP

UT P

OWER

(dBm

)

TA = -40°C

TA = +85°C

TA = +25°C

-40

-35

-30

-25

-20

-15

-10

-5

0

0 1.00.5 1.5 2.0 2.5 3.0

MODULATOR CARRIER SUPRESSIONvs. PC VOLTAGE (ENX2) = VCC

MAX

2721

TOC

51

PC VOLTAGE (V)

CARR

IER

SUPP

RESS

ION

(dBc

)

TA = -40°C

TA = +25°C

TA = +85°C

-40

-35

-30

-25

-20

-15

-10

-5

0

0 1.00.5 1.5 2.0 2.5 3.0

MODULATOR SIDEBAND SUPPRESSIONvs. PC VOLTAGE (ENX2 = VCC)

MAX

2721

TOC

52

PC VOLTAGE (V)

SIDE

BAND

SUP

PRES

SION

(dBc

)

TA = -40°C

TA = +85°C

TA = +25°C

MAX2721

MA

X2

72

0/M

AX

27

21


14 ______________________________________________________________________________________

-60

-50

-40

-30

-20

-10

0

10

20

10 1000100 10,000

MODULATOR OUTPUT POWERvs. INPUT LEVEL (TA = +85°C)

MAX

2721

TOC

55

INPUT LEVEL (mVp-p)

OUTP

UT P

OWER

(dBm

)

VPC = 2.5V

VPC = 1.5V

VPC = 2.0V

VPC = 1.0V

VPC = 0.5V

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

0 0.5 1.0 1.5 2.0 2.5 3.0

MODULATOR OUTPUT IP3 vs. PC VOLTAGE

MAX

2721

TOC

56

INPUT LEVEL (mVp-p)

OUTP

UT IP

3 (d

Bm)

TA = -40°C

TA = +85°C

TA = +25°C

-20

-15

-10

-25

15

10

-5

0

5

20

25

1.50.5 1.0 2.0 2.5

MODULATOR OUTPUT P1dB COMPRESSION POINT vs. PC VOLTAGE

MAX

2720

/21t

oc57

PC VOLTAGE (V)

OUTP

UT P

1dB

(dBm

)

TA = +85°C

TA = +25°C

TA = -40°C

1.0

1.4

1.8

2.0

2.4

2.6

MAX

2721

toc5

8

2100 2180 2260 2340 2420 2500

LO PORT VSWR vs. LO FREQUENCY(ENX2 = VCC)

FREQUENCY (MHz)

VSW

R

-60

-50

-40

-30

-20

-10

0

10

20

10 1000100 10,000

MODULATOR OUTPUT POWERvs. INPUT LEVEL (TA = +25°C)

MAX

2721

TOC

54INPUT LEVEL (mVp-p)

OUTP

UT P

OWER

(dBm

)

VPC = 2.5V

VPC = 1.5V

VPC = 2.0V

VPC = 1.0V

VPC = 0.5V


MAX2721

-60

-50

-40

-30

-20

-10

0

10

20

10 1000100 10,000

MODULATOR OUTPUT POWERvs. INPUT LEVEL (TA = -40°C)

MAX

2721

TOC

53

INPUT LEVEL (mVp-p)

OUTP

UT P

OWER

(dBm

)

VPC = 2.5V

VPC = 1.5V

VPC = 2.0V

VPC = 1.0V

VPC = 0.5V

MA

X2

72

0/M

AX

27

21


______________________________________________________________________________________ 15

8

10

9

11

12

14

13

16

15

17

18

2.7 2.92.8 3.0 3.1 3.2 3.3

PA DRIVER OUTPUT P1dB vs. SUPPLY VOLTAGE

MAX

2720

/21t

oc63

SUPPLY VOLTAGE (V)

OUTP

UT P

1dB

(dBm

)

TA = +85°C

TA = +25°C

TA = -40°C

1.0

1.4

1.6

1.8

2.0

MAX

2721

toc5

9

LO PORT VSWR vs. FREQUENCY(ENX2 = GND)

1050 1090 1130 1170

FREQUENCY (MHz)

1210 1250

VSW

R

10

11

13

12

14

15

2.7 2.92.8 3.0 3.1 3.2 3.3

PA DRIVER GAIN vs. SUPPLY VOLTAGE

MAX

2721

TOC

61SUPPLY VOLTAGE (V)

GAIN

(dB)

TA = +25°CTA = -40°C

TA = +85°C

-2

2

0

4

6

10

8

14

12

16

18

2100 2200 2300 2400 2500

PA DRIVER GAIN vs. RF FREQUENCY

MAX

2720

/21t

oc64

RF FREQUENCY (MHz)

GAIN

(dB)

TA = +25°CTA = +85°C

TA = -40°C

20

22

21

23

24

26

25

28

27

29

30

2.7 2.92.8 3.0 3.1 3.2 3.3

PA DRIVER OUTPUT IP3 vs. SUPPLY VOLTAGE

MAX

2720

/21t

oc62

SUPPLY VOLTAGE (V)

OUTP

UT IP

3 (d

Bm) TA = +85°C

TA = -40°C

TA = +25°C


20

22

21

23

24

26

25

28

27

29

2100 2200 2300 2400 2500

PA DRIVER OUTPUT IP3 vs. FREQUENCY

MAX

2720

/21t

oc65

FREQUENCY (MHz)

OUTP

UT IP

3 (d

Bm) TA = +85°C

TA = +25°C

TA = -40°C

MAX2721

MA

X2

72

0/M

AX

27

21


16 ______________________________________________________________________________________

0

2

1

3

4

6

5

8

7

9

10

2100 2200 2300 2400 2500

PA DRIVER NOISE FIGURE vs. FREQUENCY

MAX

2720

/21t

oc67

FREQUENCY (MHz)

NOIS

E FI

GURE

(dB)

TA = +25°C

TA = -40°CTA = +85°C

-15

-10

5

10

15

2.0

-25 -15 -10-20 -5 -50 10 2015

PA DRIVER OUTPUT POWER vs. INPUT POWER

MAX

2720

/21t

oc68

INPUT POWER (dBm)

OUTP

UT P

OWER

(dBm

)

TA = -40°C

TA = +85°C

TA = +25°C


MAX2721

0

4

2

6

8

12

10

16

14

18

20

2100 2200 2300 2400 2500

PA DRIVER OUTPUT P1dBvs. FREQUENCY

MAX

2720

/21t

oc66

FREQUENCY (MHz)

OUTP

UT P

1dB

(dBm

)

TA = +25°C

TA = +85°C

TA = -40°C

MA

X2

72

0/M

AX

27

21


______________________________________________________________________________________ 17

Detailed DescriptionThe MAX2720/MAX2721 upconvert in-phase (I) andquadrature (Q) baseband signals directly to RFfrequencies of 1700MHz to 2100MHz (MAX2720) or2100MHz to 2500MHz (MAX2721). They are designedfor wideband-CDMA and WLL systems where direct I/Qmodulation of the RF carrier reduces system cost, com-ponent count, and board space compared todual-conversion architectures.

Internally, the MAX2720/MAX2721 include an I/Q mod-ulator, a variable gain amplifier (VGA), and a PA driver.Separate modulator output and PA driver input portsallow insertion of a bandpass filter between the modulatorand PA driver for increased noise rejection. Disable thestand-alone PA driver to reduce current consumption.A low-power shutdown mode further reduces currentconsumption to less than 0.1µA. Additionally, a logic-level control disables or enables an internal frequencydoubler that allows the external LO to run at full or halffrequency.

NAME FUNCTION

1, 5, 10, 19, EP GNDGround. Connect to ground plane with lowest inductance path. Solder exposed paddleevenly to the board ground plane.

2 DROUTPA Driver Open-Collector Output Port. Requires an external matching network and a pull-up inductor to VCC for proper biasing. See Typical Application Circuit for recommendedcomponent values.

PIN

3 SHDNShutdown Control Input. Drive with a logic-level high to enable the device. Drive with a logic-level low to disable the device. Bypass with a 1000pF capacitor to ground, as close to thepin as possible to minimize the amount of external noise coupled onto the control line.

4, 6, 9, 12, 15 VCCSupply Voltage Input. Bypass to ground with the specified capacitor as close to the pin aspossible. (See Typical Application Circuit.)

16 ENX2

Logic-Level Enable Input for LO Doubler. Drive with a logic-level low to enable the doubler,allowing the external LO to run at half-frequency, fLO = fOUT / 2. Drive with a logic-levelhigh to disable the doubler, and allow the external LO to run at full-frequency, fLO = fOUT.Bypass with a 1000pF capacitor to ground as close to the pin as possible to minimizenoise coupled into the control line.

13, 14 Q+, Q-Quadrature Differential Input Ports. Requires DC-blocking capacitors. See Typical ApplicationCircuit for recommended component values.

11 LOLocal Oscillator input. Internally matched to 50Ω over the operating frequency band.Requires a DC-blocking capacitor. See Typical Application Circuit for recommended com-ponent values.

7, 8 I-, I+In-Phase Differential Input Ports. Requires DC-blocking capacitors. See Typical ApplicationCircuit for recommended component values.

20 DRIN

PA Driver Amplifier Input Port. Requires an external matching network and a DC-blockingcapacitor that can be part of the matching network. See Typical Application Circuit for rec-ommended component values. Connect to ground to disable the PA Driver and reducesupply current.

18 PCModulator Power Control Input. Apply a voltage between 0.5V to 2.5V to vary the outputpower of the I/Q modulator over a 30dB range. Bypass with a 1000pF capacitor to groundas close to the pin as possible to minimize noise on the control line.

17 MODOUTModulator Open-Collector Output Port. Requires an external matching network and a pull-up inductor to VCC for proper biasing. See Typical Application Circuit for recommendedcomponent values.

Pin Description

MA

X2

72

0/M

AX

27

21


18 ______________________________________________________________________________________

I/Q ModulatorThe MAX2720/MAX2721 modulator is composed of a pairof matched double-balanced mixers, an active LO quad-rature generator, and a summing amplifier. The pair ofmixers accept differential I/Q baseband signals thatdirectly modulate the internal 0° and 90° LO signalsapplied to the I/Q mixers. An external LO source drivesan internal LO quadrature generator that shifts the phaseof the LO signal applied to the Q mixer by 90° relative tothe LO signal applied to the I channel mixer. The modu-lated output of the I/Q mixers is summed together, andthe undesired sideband is suppressed.

The I+, I-, Q+, and Q- input ports feature high-linearitybuffer amplifiers with a -1dB bandwidth of 20MHz anda -3dB bandwidth of 38MHz (1kΩ I/Q source imped-ance), and accept differential input voltages up to630mVp-p. Input bandwith can be extended to beyond100MHz by lowering the I/Q source impedance. Theports are internally biased and therefore require DC-blocking capacitors. For single-ended operation,bypass the I- and Q- ports with a capacitor to groundequal in value to the DC-blocking capacitors used onthe I+ and Q+ ports. See the Typical Application Circuitfor recommended component values.

Variable Gain Amplifier (VGA)A VGA follows the summing amplifier of the I/Q modulator.Apply a voltage between 0.5V and 2.5V to PC to varythe output power of the modulator over a 32dB span.

The open-collector MODOUT output requires a pull-upinductor to VCC for proper biasing, an external matchingnetwork for optimum power transfer, and a DC-blockingcapacitor. Since the MAX2720/MAX2721 are optimizedfor different frequency ranges, they require differentoutput matching networks. See the MAX2720 and

MAX2721 Typical Application Circuit for recommendedcomponent values. See Table 1 for matching to otherfrequencies.

LO Buffer and LO Frequency DoublerThe MAX2720/MAX2721 feature an internal LO frequencydoubler that allows the external LO source to run at full orhalf frequency (Table 2). Operating the LO at half fre-quency reduces injection-pulling of the voltage-con-trolled oscillator (VCO) from the PA, and reduces thecomplexity of designing a high-frequency VCO. Aninternal two-pole bandpass filter is integrated beforethe LO phase-shift network to help reduce LO harmoniccontent and spurious mixing.

To enable the LO frequency doubler, drive ENX2 to alogic-level low and operate the external LO source athalf the RF carrier frequency. To disable the LOfrequency doubler, drive ENX2 to a logic-level high andrun the external LO source at the RF carrier frequency.See Table 2 for LO input frequency ranges.

The LO port is a single-ended input that achieves aVSWR of better than 2:1 over the specified LO inputfrequency range. Since the port is internally terminatedwith 50Ω, it requires a DC-blocking capacitor. See theTypical Applications Circuits for recommended compo-nent values. For optimum performance, drive the LOport with an input power of -16dBm to -10dBm. Drivingthe LO port with lower input power levels may affectquadrature performance, while higher input powersmay increase LO leakage.

PA Driver AmplifierThe PA driver provides a gain of 13.5dB for theMAX2720 and 11.5dB for the MAX2721. The DRINinput port requires an external matching network and a

-71.0

-68.9

-93.80.8320.896

-91.3

-66.6

0.861

S22 PHASE(degrees)

0.9091750

1800

-77.1

75.4

-97.10.8660.878

-94.8

-74.6

0.834

-73.0

0.8681950

2000

-94.70.8070.871

-94.40.8110.8841850

1900

-86.50.8610.914

S22 PHASE(degrees)

S22 MAGS22 MAGFREQUENCY

(MHz)

1700

2200

2150

2100

FREQUENCY(MHz)

2400

2350

2300

2250

Table 1. VGA MODOUT S22 Parameters (VCC = 3.0V, VPC = 2.5V, TA = +25°C)

82.5

-79.6

-104.50.9050.897

-100.50.8910.8922050

2100 2500

2450

MAX2720 MAX2721

MA

X2

72

0/M

AX

27

21


______________________________________________________________________________________ 19

DC-blocking capacitor that can be part of the matchingnetwork. The DROUT open-collector output portrequires an external matching network and a pull-upinductor to VCC for proper biasing. The pull-up inductoris incorporated as part of the matching network. Seethe MAX2720 and MAX2721 Typical Application Circuitfor recommended component values. Refer to Table 3for matching to other frequencies.

If the additional gain of the PA driver is not required,disable the PA driver to reduce current consumption.To disable the PA driver, short pin 20 (DRIN) to groundand leave pin 2 unconnected.

ShutdownApply a logic-level high to the SHDN pin to enable theMAX2720/MAX2721. Apply a logic-level low voltage todisable the device and reduce supply current to lessthan 0.1µA.

Applications InformationLayout Considerations

A properly designed PC board is an essential part ofany RF circuit. A ground plane is essential. Keep RFsignal lines as short as possible to reduce losses, radi-ation, and inductance. Use separate, low-inductancevias to the ground plane for each pin. For best perfor-mance, solder the exposed pad on the bottom of thedevice package evenly to the board ground plane.Remove the ground plane under the external VCO andlowpass filters to reduce the effects of parasitic capaci-

tance. In direct I/Q modulator applications, radiatedpower from the PA can couple into the VCO tank. Toreduce PA injection-pulling, the external VCO should behoused in a separate shielded compartment if possible.

Power-Supply, Logic, and PCInput Bypassing

Proper voltage supply bypassing is essential for high-fre-quency circuit stability. With the exception of pin 6,bypass all VCC pins with a 470pF capacitor as close tothe VCC pins as possible. The decoupling capacitor forpin 6 also serves as part of an on-chip matching network,so it should be chosen to resonate out series inductanceon the board. Some empirical adjustment may yieldincreased output power. See the MAX2720/MAX2721Typical Application Circuit for suggested values.

Bypass the ENX2, SHDN, and PC inputs with a 1000pFcapacitor to ground to minimize noise injected into thedevice. Use a series resistor (10kΩ typ) to furtherreduce coupling of high-frequency signals into thedevice.

Voltage supply layout is also critical to achieve optimumperformance. The IC has several RF processing stagesthat use the various VCC pins, and while they haveon-chip decoupling, off-chip interaction between themmay degrade gain, linearity, carrier suppression, andoutput power control range. The supplies associatedwith pins 2, 6, 15 (MAX2721 only), and 17 lie directly inthe RF signal path. Pins 4, 12, and 15 carry LO signalcurrents, so it is important to keep them from interactingwith the RF signal path to prevent poor carrier suppres-sion. The VGA generates discarded signal currents onpin 4, which also need to be kept away from the signalpath supplies. Because there is a great deal of gain following from the first RF stage, it is also important toprevent coupling from pins 2, 4, 15, and 17 to pin 6;excessive coupling may degrade stability.

2100 to 2500

1050 to 1250

1700 to 2100

MAX2721

850 to 1050Low

High

MAX2720

LO INPUT FREQUENCY RANGE (MHz)ENX2LOGIC LEVEL

Table 2. LO Input Frequency Range

MA

X2

72

0/M

AX

27

21


20 ______________________________________________________________________________________

Table 3. PA Driver S-Parameters (VCC = 3.0V, TA = +25°C)

0.125

0.110

0.117

0.118

0.123

0.106

0.106

2.848

3.176

3.087

3.013

2.929

3.360

3.268

-97.8

-133.9

-153.1

-141.0

-144.9

-142.7

47.02500 0.425 40.9 0.015130.3

-138.9

80.4

71.7

63.5

55.4

96.2

2350

2300 0.456 75.9 0.051

0.462 67.9 0.042

87.4

2450

2400 0.447

135.8

59.7

135.3

0.031

0.437 51.6 0.026

132.9

132.2

2250

2200 0.475 88.0 0.055

0.473 84.2 0.046

139.0

136.9

0.1023.492 -138.0104.22150 0.470 97.2 0.066141.3

0.100

FREQUENCY(MHz)

S11 MAG S21 PHASE S22 MAG

0.105

0.093

0.093

0.091

0.096

S12 MAG

0.092

0.097

3.690

3.567

4.370

4.160

3.946

3.801

S21 MAG

4.708

4.389

S22 PHASE

-120.3

-128.8

-109.2

-118.4

-100.8

-111.0

-82.4

120.4

112.32100

2050 0.440 112.8 0.083

0.452 104.9 0.082

142.8

-99.5

153.5

144.3

135.2

128.4

S21 PHASE

178.1

142.9

1900

1850 0.418 138.2 0.123

0.449 129.7 0.095

161.7

2000

1950 0.421

149.4

128.7

145.3

0.082

0.425 121.2 0.091

140.1

142.8

1800

1700 0.321

S11 PHASE

164.7 0.162

0.383 147.2 0.142

151.6

152.0

0.0944.588 -90.3171.51750 0.347 154.2 0.158152.7

MA

X2

72

0/M

AX

27

21


______________________________________________________________________________________ 21

Typical Application Circuit

20

19

18

17

16

15

14

13

1

2

3

4

5

6

7

8

12

11

9

10

VCC

DROUT

GND

I+

I-

VCC

GND

GND

VCC

SHDN

DRIN

GND

PC

MODOUT

VCC

Q-

Q+

VCC

LO

ENX2

MAX2720MAX2721

0.1µF

VCC

470pF

0.1µF

8pF (5pF*)VCC

470pFVCC1000pF

100k

2.0pF

470pF

3.9nH

VCC

PA DRIVEROUTPUT

PA DRIVERINPUT

SHUTDOWNCONTROL

LO DOUBLERENABLE

VGA POWERCONTROL

I MODULATION Q MODULATION

LO INPUT

47pF

VCC

470pF

0.1µF

3pF

0.1µF

470pFVCC

1.0pF (27pF*)

470pF

1.5nH(1.2nH*)

0nH(3.3nH*)

VCC

MODOUTOUTPUT

10k

1000pF

100k

1000pF

*COMPONENT VALUE FOR MAX2721 0NLY.

MA

X2

72

0/M

AX

27

21


22 ______________________________________________________________________________________

Chip InformationTRANSISTOR COUNT: 1041

20

19

18

17

16

15

14

13

1

2

3

4

5

6

7

8

DRIN

GND

PC

MODOUTVCC

DROUT

GND

TOP VIEW

VCC

Q-

Q+I+

I-

VCC

GND

12

11

9

10

VCC

LOGND

VCC

MAX2720MAX2721

TSSOP-EP

SHDN

ENX2

Pin Configuration

MA

X2

72

0/M

AX

27

21


______________________________________________________________________________________ 23

Package Information

TSS

OP

.EP

S

MA

X2

72

0/M

AX

27

21


Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

24 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

24 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

NOTES

Documents

1.7GHz to 2.5GHz, Direct I/Q Modulator with VGA and PA Driver · CDMA and wireless local-loop (WLL) systems. Their direct-upconversion architecture reduces system cost, component