Switched-capacitor impedance simulation circuits realized with simplified circuit structure

Abstract

This paper describes switched-capacitor (SC) inductor and Frequency Dependent Negative Resistor (FDNR) which use unity gain buffer (UGB) in common with another SC circuit to simplify circuit structure. Though common use of UGB has been reported in many references, UGB is usually connected to the same nodes and it often suffers simplification of SC circuits. In this paper, UGB is used in common with another SC circuit in a different way and SC inductor with simpler structure is obtained. The circuit is controlled by a simple two phase control clock. The capacitor value spreads and the sum of capacitor values is small. The number of capacitors needed is four. Then this SC inductor is modified to introduce SC FDNR. The sum of capacitor values and number of capacitors in the SC FDNR are the smallest value in SC FDNR circuits reported so far. To confirm basic operations of circuits proposed, simulation results by SWITCAP are also shown.