LMX3161

Single Chip Radio Transceiver

General Description

The LMX3161 Single Chip Radio Transceiver is a monolithic,

integrated radio transceiver optimized for use in a Digital En-

hanced Cordless Telecommunications (DECT) system. It is

fabricated using National’s ABiC V BiCMOS process

(f

The LMX3161 contains phase locked loop (PLL), transmit

and receive functions. The 1.1 GHz PLL block is shared be-

tween transmit and receive section. The transmitter includes

a frequency doubler, and a high frequency buffer. The re-

ceiver consists of a 2.0 GHz low noise mixer, an intermediate

frequency (IF) amplifier, a high gain limiting amplifier, a fre-

quency discriminator, a received signal strength indicator

(RSSI), and an analog DC compensation loop. The PLL,

doubler, and buffers can be used to implement open loop

modulation along with an external VCO and loop filter. The

circuit features on-chip voltage regulation to allow supply

voltages ranging from 3.0V to 5.5V. Two additional voltage

regulators provide a stable supply source to external dis-

crete stages in the Tx and Rx chains.

The IF amplifier, high gain limiting amplifier, and discrimina-

tor are optimized for 110 MHz operation, with a total IF gain

of 85 dB. The single conversion receiver architecture pro-

vides a low cost, high performance solution for communica-

tions systems. The RSSI output may be used for channel

quality monitoring.

The Single Chip Radio Transceiver is available in a 48-pin

7mm X 7mm X 1.4mm PQFP surface mount plastic pack-

age.

Features

n Single chip solution for DECT RF transceiver

n RF sensitivity to −93 dBm; RSSI sensitivity to −100 dBm

n Two regulated voltage outputs for discrete amplifiers

n High gain (85 dB) intermediate frequency strip

n Allows unregulated 3.0V–5.5V supply voltage

n Power down mode for increased current savings

n System noise figure 6.5 dB (typ)

Applications

n Digital Enhanced Cordless Telecommunications (DECT)

n Personal wireless communications (PCS/PCN)

n Wireless local area networks (WLANs)

n Other wireless communications systems

Block Diagram

DS012815-1

PRELIMINARY

November 1999

© 1999 National Semiconductor Corporation

DS012815

www.national.com