High-precision, programmable 1-10 MHz bandwidth, 0-20 dB gain communication channel for digital video applications

The analog signal processing portion of a digital video demodulation scheme is built in a 5 V BiCMOS process. The channel is both cutoff frequency and gain programmable from 1/spl rarr/10 MHz and 0/spl rarr/20 dB, respectively. The filter is realized as a 4/sup th/ order Gm/C Butterworth lowpass and includes in-package trim for accurate control. A programmable gain amplifier is placed in front of the filter for better S/N performance (>40 dB) and lower intermodulation distortion (>-52 dB). The PSRR of this single-ended channel is better than 40 dB. The channel dissipates 250 mW.