Intermediate-frequency/baseband analog processing chipset for a CDMA/AMPS mobile handset

An intermediate-frequency/baseband analog processing chipset (BBA) has been developed for CDMA/AMPS mobile handset applications. The chipset is compri sed of two 48-pin chips for the receive and the transmit paths. They includ e variable gain amplifiers, continuous time filters, a quadrature modulator and demodulator, a 4-bit analog-to-digital converter, an 8-bit digital-to- analog converter, an LC-tuned voltage controlled oscillator (VCO) with exte rnal tank, a charge pump phase locked loop (PLL), and a three-line serial p ort interface for mode control. A programmable temperature compensation tec hnique is employed to meet the stringent temperature requirements. The chip set has been fabricated using a 15-GHz 0.5-mum BiCMOS process. The chip per formance has successfully met the required specifications for dual-mode han dsets.