A BiCMOS continuous-time filter for video signal processing applications

A fully integrated BiCMOS continuous-time filter for video signal processing applications is presented. It incorporates an input clamping circuit, a third-order equalizer, a fifth-order elliptic filter with sinx/x correction, and a 75-/spl Omega/ driver. The architectures of the input and output amplifiers as well as the filter and the equalizer are chosen based on the extensive study of circuit structures and Monte Carlo simulation to meet the linearity requirement for the broadcast-quality video system. The complete chip achieves a low-pass filter response with a 5.5-MHz cutoff frequency (f/sub cc/), 0.3-dB passband ripple, 20-ns group delay variation up to 0.9 f/sub c/, and 43-dB attenuation at 1.45 f/sub c/. With a nominal 2-Vpp signal at the output, measured results show 0.2% differential gain, 0.38/spl deg/ differential phase, and 1.7-mV rms noise demonstrating 10-bit linearity in a 1.5-/spl mu/m 4-GHz BiCMOS process technology. The filter active area is 8 mm/sup 2/ and it dissipates 350 mW in a single 5-V power supply.