________________General Description

The MAX2424/MAX2426 highly integrated front-end ICs

provide the lowest cost solution for cordless and ISM-

band 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 trans-

mit 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-mod-

ulus prescaler can also be set to a direct mode, in which

it acts as an LO buffer amplifier. Four separate power-

down inputs can be used for system power manage-

ment, including a 0.5µA shutdown mode.

The MAX2424/MAX2426 come in a 28-pin SSOP pack-

age.

________________________Applications

Cordless Phones

Wireless Telemetry

Wireless Networks

Spread-Spectrum Communications

Two-Way Paging

____________________________Features

o Receive Mixer with 35dB Image Rejection

o Adjustable-Gain LNA

o Up to +2dBm Combined Receiver Input IP3

o 4dB Combined Receiver Noise Figure

o Optimized for Common Receiver IF Frequencies:

10.7MHz (MAX2424)

70MHz (MAX2426)

o PA Predriver Provides up to 0dBm

o Low Current Consumption: 23mA Receive

20mA Transmit

9.5mA Oscillator

o 0.5µA Shutdown Mode

o Operates from Single +2.7V to +4.8V Supply

900MHz Image-Reject Receivers

with Transmit Mixer

________________________________________________________________

Maxim Integrated Products

1

28

27

26

25

24

23

22

21

20

19

18

17

16

15

1

2

3

4

5

6

7

8

9

10

11

12

13

14

GND

GND

GND

TANK

TXON

PREOUT

PREGND

MOD

DIV1

VCOON

RXON

CAP2

TXIN

TXIN

LNAGAIN

TXOUT

GND

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.