High-speed programmable analog transversal filter having a large dynamic range

摘要

A programmable analog transversal filter suitable for monolithic Bipolar-Complimentary-Metal-Oxide Semiconductor (BiCMOS) realization. The tap weights are digitally programmable by capacitor- switching responsive to binary input signals. Speed is improved by combining the multiplication and summation functions into a single capacitor array without operational amplifiers. A continuous analog input signal is filtered to produce a discrete time analog output signal, which may be made continuous by adding a low-pass filter. The capacitor array performs both multiplication and summation functions simultaneously and automatically normalizes the resulting output signal. Because no operational amplifiers are used in the multiplication/summation functions, they are not limited by operational amplifier dynamic range and slew- rate.