General Description

The MAX1479 crystal-referenced phase-locked-loop

(PLL) VHF/UHF transmitter is designed to transmit ASK,

OOK, and FSK data in the 300MHz to 450MHz frequency

range. The MAX1479 supports data rates up to 100kbps

in ASK mode and 20kbps in FSK mode (both

Manchester coded). The device provides an adjustable

output power of more than +10dBm into a 50

Ω load. The

crystal-based architecture of the MAX1479 eliminates

many of the common problems of SAW-based transmit-

ters by providing greater modulation depth, faster fre-

quency settling, higher tolerance of the transmit

frequency, and reduced temperature dependence.

These improvements enable better overall receiver per-

formance when using the MAX1479 together with a

superheterodyne receiver such as the MAX1470,

MAX1471, MAX1473, or MAX7033.

The MAX1479 is available in a 16-pin thin QFN pack-

age (3mm x 3mm) and is specified for the automotive

temperature range from -40°C to +125°C.

Applications

Remote Keyless Entry

Tire Pressure Monitoring

Security Systems

Radio-Controlled Toys

Wireless Game Consoles

Wireless Computer Peripherals

Wireless Sensors

RF Remote Controls

Garage Door Openers

Features

♦ ETSI-Compliant EN300 220

♦ +2.1V to +3.6V Single-Supply Operation

♦ Supports ASK, OOK, and FSK Modulations

♦ Adjustable FSK Shift

♦ +10dBm Output Power into 50Ω Load

♦ Low Supply Current (6.7mA in ASK Mode,

and 10.5mA in FSK Mode)

♦ Uses Small Low-Cost Crystal

♦ Small 16-Pin Thin QFN Package

♦ Fast-On Oscillator—200µs Startup Time

♦ Programmable Clock Output

300MHz to 450MHz Low-Power,

Crystal-Based +10dBm ASK/FSK Transmitter

________________________________________________________________ Maxim Integrated Products

1

16

15

14

13

9

10

11

12

CLK0

CLK1

DEV0

DEV1

TOP VIEW

4

3

2

1

ENABLE

EP

DIN

MODE

56

7

8

MAX1479

THIN QFN

(3mm x 3mm)

Pin Configuration

Ordering Information

MAX1479

ENABLE

DIN

MODE

CLK0

CLK1

DEV0

DEV1

CRYSTAL

DRIVER

4

3

2

1

5

6

7

8

9

10

11

12

13

14

15

16

CLOCK

DIVIDER

DIVIDE

BY 32

LOOP

FILTER

ASK

FSK

PA

ENVELOPE

SHAPING

DEVIATION

PD/CP

VCO

Functional Diagram

19-3353; Rev 0; 8/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

*EP = Exposed paddle.

PART

TEMP RANGE

PIN-PACKAGE

MAX1479ATE

-40°C to +125°C

16 Thin QFN-EP*

Typical Application Circuit appears at end of data sheet.