DESIGN OF A HIGH PRECISION SAMPLE-AND-HOLD CIRCUIT FOR A/D CONVERTER

Abstract

A new CMOS switch circuit for the implementation of high precision sample-and-hold and a high gain, broad bandwidth operational amplifier are described. The switch includes a current mirror and switching action is controlled by current pulses. This reduces charge injection due to clock feed through and the charge injection is input signal independent, resulting in a greatly improved sample-and-hold accuracy. The operational amplifier employed a high output swing, and high output impedance design known as regulated cascade as active load. The layout of the operational amplifier developed are shown as well.