DESCRIPTION

The SA9504 is an integrated receiver front-end for 900 MHz Cellular (AMPS) and 1.9 GHz PCS (CDMA) phones. This dual-band receiver circuit has low noise amplifiers and downconverters for both bands, and provides an elegant solution for RF-to-IF conversion.

The two cascode LNAs have been designed to provide high gain with very low noise figures and high linearity. The downconverter portion is based on the Philips SA9502. There are two individual mixer blocks, each optimized for low noise figure and high linearity. The whole circuit is designed for low power consumption, high performance, and is compatible with the requirements for Cellular (AMPS) and PCS (CDMA) handsets.

The circuit has been designed in our advanced QUBiC3 BiCMOS process with 30 GHz fT and 60 GHz fMAX.

FEATURES

LNA typical performance

• LNAs for both Cellular (AMPS) and PCS (CDMA) bands

• High gain, low noise figure, high linearity performance

• Cascode output structure requiring no external matching

• Low power consumption, typical 4.9 mA

• Low voltage operation down to 2.7 volts

Downconverter typical performance

• Separate, selectable IF outputs to suit FM and CDMA bandwidths

• Buffered Cellular and PCS LO inputs

• Integrated frequency doubler for PCS mixer LO

• Differential (Tx) LO output buffer (can be switched on or off)

• Low voltage operation down to 2.7 volts

• Mixers current consumption with (Tx) LO buffer on:

– Cellular FM: 17.4 mA

– PCS: 27.6 mA

• Low standby current in sleep mode: <50 µA

• Small LQFP32 package

APPLICATIONS

• 800 MHz analog FM and receivers

• 1.9 GHz PCS (CDMA) digital receivers

• Supports dual-band operation

• Digital mobile communications equipment

• Portable, low power radio equipment