A dual-channel QAM/QPSK receiver IC with integrated cable set-top box functionality

A digital cable-TV receiver IC with a 5 MBaud 64/256-QAM in-band channel and a 1 MBaud QPSK out-of-band channel incorporating on-chip forward error correction, tracking loops and adaptive decision feedback equalizers has been designed. The device further integrates out-of-band message separation and peripheral box control circuitry. The chip interfaces to a MC-68331 microprocessor and uses a mix of semicustom and custom design methodologies to achieve functionality in an 8 mm/spl times/8 mm die area with a 0.5 /spl mu/m CMOS technology, while dissipating 1.8 W at 5 V in a 208-pin PQFP package.