Two-port analysis of switched-capacitor networks using four-port equivalent circuits in the z-domain

Abstract

In a previous publication by the authors it was shown how switched-capacitor (SC) networks can be analyzed by using nodal charge equations. The result was a description of SC networks as time-variant sampled-data networks which led to a four-port equivalent circuit representation in the z-domain. In this paper, the four-port representation is expanded by considering six basic building blocks for the design of any general active or passive SC network. With the four-port equivalent circuit representation, traditional two-port analysis tools, such as the transmission matrix and two-port transfer functions, can be used conveniently. An SC-filter design example is given and the measured response is shown to coincide with the response predicted by the theory.