TLW12459

PRELIMINARY

August 1996

LMX2305

PLLatinum

for RF Personal Communications

General Description

The LMX2305 is a high performance frequency synthesizer

with an integrated prescaler designed for RF operation up to

550 MHz It is fabricated using National’s ABiC IV BiCMOS

process

The LMX2305 contains a dual modulus prescaler which can

select either a 6465 or a 128129 divide ratio at input fre-

quencies of up to 550 MHz LMX2305 which employs the

digital phase lock loop technique combined with a high

quality reference oscillator and a loop filter provides the

tuning voltage for the voltage controlled oscillator to gener-

ate a very stable low noise local oscillator signal

Serial data is transferred into the LMX2305 via a three line

age can range from 265V to 55V The LMX2305 features

very low current consumption typically 40 mA at 275V

The LMX2305 is available in a TSSOP 20-pin surface mount

plastic package

Features

Y

RF operation up to 550 MHz

Y

265V to 55V operation

Y

Low current consumption

Y

Dual modulus prescaler 6465 or 128129

Y

Internal balanced low leakage charge pump

Y

Small-outline plastic surface mount TSSOP

0173

wide package

Applications

Y

Analog Cellular telephone systems

(AMPS ETACS NMT)

Y

Portable wireless communications

(PCSPCN cordless)

Y

Wireless local area networks (WLANs)

Y

Other wireless communication systems

Y

Pagers

Block Diagram

TLW12459 – 1

TRI-STATE

is a registered trademark of National Semiconductor Corporation

C1996 National Semiconductor Corporation

RRD-B30M126Printed in U S A

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