MOS sampled data recursive filters using switched capacitor integrators

A new technique to analog sampled data filtering is presented which can be fully integrated using MOS technology. Advantages of this new approach are reduced circuit complexity, low sensitivity to coefficient variations, and efficient utilization of silicon area. Performance of monolithic low Q(Q=1) and high Q(Q=73) filters are presented which were implemented using NMOS technology. In implementing the high Q filter a new operational amplifier design was used which had a 14-V output range, rms noise voltage of 45 /spl mu/V, an open-loop gain of 6000, and a unity-gain bandwidth of 2 MHz.