A new method to increase the dynamic range of switched op amp delta-sigma modulators

Abstract

Switched op amp technique has shown its capability to operate with very low supply voltages without a demand for voltage multiplication. But it has not achieved the performance of the switched capacitor circuits yet. In this paper one of the nonideal factors, which degrades the performance of the switched Op amp circuits, has been introduced and a solution has been proposed for it. A second order delta-sigma modulator has been designed with this method and has achieved an excellent DR of 90 dB and a very low power consumption of 200 /spl mu/W while operating with a 1.8-volt supply.