Switched-capacitor realization of Nth-order transfer function using a single multiplexed op-amp

This paper presents SC circuits for realizing an arbitrary
N
th-order filter function using any number of op-amps, from 1 to
N
. The reduced op-amp. count is obtained at the cost of an increased number of clock phases. Low-noise and low-sensitivity structures are obtained by applying the recently proposed methods of Intermediate-Function Synthesis. An experimental prototype of a 5th-order low-pass filter example is used to verify the proposed multiplexing scheme.