Maxim MAX24276EAI, MAX2424EAI Datasheet

________________General Description

The MAX2424/MAX2426 highly integrated front-end ICs provide the lowest cost solution for cordless and ISMband radios operating in the 900MHz band. Both devices incorporate a receive image-reject mixer (to reduce filter cost) as well as a versatile transmit mixer. The devices operate from a +2.7V to +4.8V single power supply, allowing direct connection to a 3-cell battery stack.

The receive path incorporates an adjustable-gain LNA and an image-reject downconverter with 35dB image suppression. These features yield excellent combined downconverter noise figure (4dB) and high linearity with an input third-order intercept point (IIP3) of up to +2dBm.

The transmitter consists of a double-balanced mixer and a power amplifier (PA) predriver that produces up to 0dBm (in some applications serving as the final power stage). It can be used in a variety of configurations, including BPSK modulation, direct VCO modulation, and transmitter upconversion. For devices featuring transmit as well as receive image rejection, refer to the MAX2420/MAX2421/MAX2422/MAX2460/MAX2463 data sheet.

The MAX2424/MAX2426 have an on-chip local oscillator (LO), requiring only an external varactor-tuned LC tank for operation. The integrated divide-by-64/65 dual-modulus prescaler can also be set to a direct mode, in which it acts as an LO buffer amplifier. Four separate powerdown inputs can be used for system power management, including a 0.5µA shutdown mode.

The MAX2424/MAX2426 come in a 28-pin SSOP package.

________________________Applications

Cordless Phones

Wireless Telemetry

Wireless Networks

Spread-Spectrum Communications

Two-Way Paging

____________________________Features

♦ Receive Mixer with 35dB Image Rejection ♦ Adjustable-Gain LNA ♦ Up to +2dBm Combined Receiver Input IP3 ♦ 4dB Combined Receiver Noise Figure ♦ Optimized for Common Receiver IF Frequencies:

10.7MHz (MAX2424) 70MHz (MAX2426)

♦ PA Predriver Provides up to 0dBm ♦ Low Current Consumption: 23mA Receive

20mA Transmit

9.5mA Oscillator

♦ 0.5µA Shutdown Mode ♦ Operates from Single +2.7V to +4.8V Supply

MAX2424/MAX2426

900MHz Image-Reject Receivers

with Transmit Mixer

________________________________________________________________

Maxim Integrated Products

GND

TANK

TXON

PREOUT

PREGND

MOD

DIV1

VCOON

RXON

CAP2

TXIN

LNAGAIN

TXOUT

GND

RXIN

GND

RXOUT

CAP1

SSOP

TOP VIEW

MAX2424 MAX2426

TANK

___________________Pin Configuration

19-1350 Rev 2; 2/99

PART

MAX2424EAI

-40°C to +85°C

TEMP. RANGE PIN-PACKAGE

28 SSOP

_______________Ordering Information

Functional Diagram appears at end of data sheet.

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

MAX2426EAI

-40°C to +85°C 28 SSOP

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769.

MAX2424/MAX2426

900MHz Image-Reject Receiver with Transmit Mixer

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +2.7V to +4.8V, no RF signals applied, LNAGAIN = Unconnected, V

TXIN

= V

TXIN

= 2.3V, V

VCOON

= 2.4V, V

RXON

= V

TXON

MOD

= V

DIV1

= 0.45V, PREGND = GND, TA= -40°C to +85°C. Typicals are at TA= +25°C, VCC= 3.3V, unless otherwise noted.)

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

Note 1: Calculated by measuring the combined oscillator and prescaler supply current and subtracting the oscillator supply current. Note 2: Calculated by measuring the combined oscillator and LO buffer supply current and subtracting the oscillator supply current. Note 3: Calculated by measuring the combined receive and oscillator supply current and subtracting the oscillator supply current.

With LNAGAIN = GND, the supply current drops by 4.5mA.

Note 4: Calculated by measuring the combined transmit and oscillator supply current and subtracting the oscillator supply current.

to GND...........................................................-0.3V to +5.5V

TXIN, TXIN Differential Voltage..............................................+2V

Voltage on TXOUT......................................-0.3V to (V

+ 1.0V)

Voltage on LNAGAIN, TXON, RXON, VCOON,

DIV1, MOD, TXIN, TXIN............................-0.3V to (V

+ 0.3V)

RXIN Input Power..............................................................10dBm

TANK, TANK Input Power...................................................2dBm

Continuous Power Dissipation (T

= +70°C)

SSOP (derate 9.50mW/°C above +70°C) ......................762mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +165°C

Lead Temperature (soldering, 10sec) .............................+300°C

PARAMETER

MIN TYP MAX UNITS

Receive Supply Current (Note 3) 23 36 mA

Prescaler Supply Current (buffer mode) (Note 2)

5.4 8.5 mA

Oscillator Supply Current

Supply-Voltage Range 2.7 4.8 V

9.5 14 mA

Prescaler Supply Current (÷ 64/65 mode) (Note 1)

4.2 6 mA

CONDITIONS

RXON

= 2.4V, PREGND = unconnected

DIV1

= 2.4V

PREGND = unconnected

Digital Input Voltage Low 0.45 V

Shutdown Supply Current

0.5

RXON, TXON, DIV1, VCOON, MOD

VCOON = RXON = TXON = MOD = DIV1 = GND

Digital Input Current ±1 ±10 µAVoltage on any one digital input = VCCor GND

Digital Input Voltage High V2.4RXON, TXON, DIV1, VCOON, MOD

µA

TA= +25°C TA= -40°C to +85°C

Transmitter Supply Current (Note 4) 20 32 mA

RXON

= 0.45V, V

TXON

= 2.4V,

PREGND = unconnected

AC ELECTRICAL CHARACTERISTICS

(MAX2424/MAX2426 EV kit, VCC= +3.3V, f

RXIN

= 915MHz, P

RXIN

= -35dBm, V

TXIN

= V

TXIN

= 2.3V (DC bias), V

TXIN

= 250mVp-p,

TXIN

= 1MHz, V

LNAGAIN

= 2V, V

VCOON

= 2.4V, RXON = TXON = MOD = DIV1 = PREGND = GND, TA= +25°C, unless otherwise noted.)

MAX2424/MAX2426

900MHz Image-Reject Receiver

with Transmit Mixer

_______________________________________________________________________________________ 3

(Note 11)

MAX2424 (Notes 5, 6)

TA= T

MIN

to T

MAX

(Note 5)

TA= +25°C

(Notes 5, 6)

(Notes 5, 10)

(Note 9)

Receiver on or off

LNAGAIN = GND (Note 7)

LNAGAIN

= 1V (Note 7)

LNAGAIN

= 1V (Notes 5, 8)

LNAGAIN = V

(Notes 5, 8)

LNAGAIN

= VCC,

TA= -40°C to +85°C (Notes 5, 7)

MAX2426 (Notes 5, 6)

LNAGAIN

= VCC,

TA= +25°C (Note 7)

LNAGAIN

= 1V (Notes 5, 7)

LNAGAIN = V

(Notes 5, 7)

CONDITIONS

dBc30Carrier Suppression

dBm3.5Output Third-Order Intercept (OIP3)

dBm-0.5Output 1dB Compression

-10 -4.5

dBm

-9.5 -7 -5

Output Power

MHz125Baseband 3dB Bandwidth

MHz800 1000Output Frequency Range

ns500Receiver Turn-On Time

dBm-60LO to RXIN Leakage

-8

-19 -17

Input Third-Order Intercept (IIP3)

Noise Figure

MHz

8.5 10.7 12.5

MHz800 1000Input Frequency Range

-16

18 24

19 25

55 70 85

IF Frequency Range

dB26 35Image Frequency Rejection

20 22 24.5

Conversion Power Gain

19 21 23.5

UNITSMIN TYP MAXPARAMETER

MAX2424 MAX2426 MAX2424 MAX2426

LNAGAIN

= 1V

LNAGAIN = V

-18

dBm

-26

Input 1dB Compression

(Note 12) ns220Transmitter Turn-On Time

dBm/Hz-140Output Noise Density

RECEIVER (V

RXON

= 2.4V, fLO= 925.7MHz (MAX2424), fLO= 985MHz (MAX2426))

TRANSMITTER (V

TXON

= 2.4V, fLO= 915MHz)

DIV1

= 2.4V, ZL= 50Ω,

MAX2424/MAX2426

900MHz Image-Reject Receiver with Transmit Mixer

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS (continued)

(MAX2424/MAX2426 EV kit, VCC= +3.3V, f

RXIN

= 915MHz, P

RXIN

= -35dBm, V

TXIN

= V

TXIN

= 2.3V (DC bias), V

TXIN

= 250mVp-p,

TXIN

= 1MHz, V

LNAGAIN

= 2V, V

VCOON

= 2.4V, RXON = TXON = MOD = DIV1 = PREGND = GND, TA= +25°C, unless otherwise noted.)

PARAMETER MIN TYP MAX UNITS

Oscillator Phase Noise

Oscillator Frequency Range 800 1100 MHz

dBc/Hz

(Note 5)

CONDITIONS

Note 5: Guaranteed by design and characterization. Note 6: Image rejection typically falls to 30dBc at the frequency extremes. Note 7: Refer to the

Typical Operating Characteristics

for a plot showing Receiver Gain vs. LNAGAIN Voltage, Input IP3 vs.

LNAGAIN Voltage, and Noise Figure vs. LNAGAIN Voltage.

Note 8: Two tones at P

RXIN

= -45dBm each, f1 = 915.0MHz and f2 = 915.2MHz.

Note 9: Time delay from V

RXON

= 0.45V to V

RXON

= 2.4V transition to the time the output envelope reaches 90% of its final value.

Note 10: Output power typically falls to -10dBm at the frequency extremes. Note 11: Two tones at V

TXIN

= 125mVp-p, f1 = 1.0MHz, and f2 = 1.2MHz.

Note 12: Time delay from V

TXON

= 0.45V to V

TXON

= 2.4V transition to the time the output envelope reaches 90% of its final value.

Note 13: Using tank components L3 = 5.0nH (Coilcraft A02T), C2 = C3 = C26 = 3.3pF, R6 = R7 = 10Ω. Note 14: This approximates a typical application in which TXOUT is followed by an external PA and a T/R switch with finite isolation. Note 15: Relative to the rising edge of PREOUT.

Prescaler Output Level

500 mVp-p

-11 -8

Required Modulus Setup Time (Notes 5, 15)

10 ns

ZL= 100kΩ

| |

10pF

÷ 64/65 mode

Required Modulus Hold Time (Notes 5, 15)

0 ns

÷ 64/65 mode

Oscillator Buffer Output Level (Notes 5, 13)

-12

dBm

DIV1

= 2.4V,

ZL= 50Ω

10kHz offset (Note 13)

Standby to TX or Standby to RX

Oscillator Pulling

kHz

110

RX to TX with P

RXIN

=-45dBm (RX mode)

to P

RXIN

= 0dBm (TX mode) (Note 14)

MAX2424 MAX2426 MAX2424 MAX2426 MAX2424 MAX2426

TA= +25°C TA= -40°C to +85°C

OSCILLATOR AND PRESCALER

MAX2424/MAX2426

900MHz Image-Reject Receiver

with Transmit Mixer

_______________________________________________________________________________________

-40 0 20-20 40 60 80

RECEIVER SUPPLY CURRENT

vs. TEMPERATURE

MAX2424/6-01

TEMPERATURE (°C)

(mA)

VCC = 2.7V

VCC = 3.3V

VCC = 4.8V

RXON = V

PREGND = UNCONNECTED INCLUDES OSCILLATOR CURRENT

-40 0 20-20 40 60 80

TRANSMITTER SUPPLY CURRENT

vs. TEMPERATURE

MAX2424/6-02

TEMPERATURE (°C)

(mA)

VCC = 2.7V

VCC = 3.3V

VCC = 4.8V

TXON = V

PREGND = UNCONNECTED INCLUDES OSCILLATOR CURRENT

1.0

0.5

2.5

2.0

1.5

4.0

3.5

3.0

4.5

-40 0 20-20 40 60 80

SHUTDOWN SUPPLY CURRENT

vs. TEMPERATURE

MAX2424/6-03

TEMPERATURE (°C)

(µA)

VCC = 2.7V

VCC = 3.3V

VCC = 4.8V

VCOON = GND

-5

-10

-15

-20 0 0.5 1.0 1.5 2.0

RECEIVER GAIN vs. LNAGAIN

MAX2424/6-04

LNAGAIN VOLTAGE (V)

RECEIVER GAIN (dB)

ADJUSTABLE

GAIN

MAX GAIN

LNA

PARTIALLY

BIASED

LNA OFF

AVOID

THIS

REGION

RXON = V

-40 0 20-20 40 60 80

MAX2424

RECEIVER GAIN vs. TEMPERATURE

MAX2424/6-07

TEMPERATURE (°C)

RECEIVER GAIN (dB)

VCC = 2.7V

VCC = 3.3V

VCC = 4.8V

LNAGAIN = V

RXON = V

-20

-15

-10

-5

0 0.5 1.0 1.5 2.0

RECEIVER INPUT IP3 vs. LNAGAIN

MAX2424/6-05

LNAGAIN VOLTAGE (V)

IIP3 (dBm)

ADJUSTABLE

GAIN

AVOID

THIS

REGION

MAX GAIN

LNA

PARTIALLY

BIASED

LNA OFF

RXON = V

0 0.5 1.0 1.5 2.0

RECEIVER NOISE FIGURE

vs. LNAGAIN

MAX2424/6-06

LNAGAIN VOLTAGE (V)

NOISE FIGURE (dB)

ADJUSTABLE

GAIN

AVOID

THIS

REGION

MAX

GAIN

LNA

PARTIALLY

BIASED

LNA OFF

RXON = V

DIV1 = V

3.0

4.0

3.5

5.0

5.5

4.5

-40 0 20-20 40 60 80

RECEIVER NOISE FIGURE vs.

TEMPERATURE AND SUPPLY VOLTAGE

MAX2424/6-08

TEMPERATURE (°C)

NOISE FIGURE (dB)

VCC = 3.3V

LNAGAIN = V

RXON = V

DIV1 = V

VCC = 4.8V

= 2.7V

-20

-16

-18

-8

-10

-6

-12

-14

-40 0 20-20 40 60 80

RECEIVER INPUT IP3

vs. TEMPERATURE

MAX2424/6-09

TEMPERATURE (°C)

IIP3 (dBm)

LNAGAIN

= 1V

RXON = V

LNAGAIN

= 2V

__________________________________________Typical Operating Characteristics

(MAX2424/MAX2426 EV kit, VCC= +3.3V; f

LO(

RX)

= 925.7MHz (MAX2424), 985MHz (MAX2426); f

RXIN

= 915MHz, P

RXIN

-35dBm, f

LO(TX)

= 915MHz, V

TXIN

= V

TXIN

= 2.3V (DC bias), V

TXIN

= 250mVp-p, f

TXIN

= 1MHz, V

LNAGAIN

= 2V, V

VCOON

= 2.4V,

RXON = TXON = MOD = DIV1 = PREGND = GND, TA= +25°C, unless otherwise noted.)

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