Buffered bootstrapped input switch with cancelled charge sharing for use in high performance sample and hold switched capacitor circuits

摘要

A buffered bootstrapped input switch employs cancelled charge sharing for use in high performance sample and hold switched capacitor circuits especially useful for implementing, for example, an analog-to-digital converter (ADC) or amplifier circuit front end sampling network, among others. A scheme is employed for estimating the charge loss from the bootstrapping capacitor to the gate of the bootstrapped input switch, storing the estimated charge loss on a small capacitor, buffering the small capacitor, and then adding the estimated charge loss in series to the bootstrap capacitor, to provide an almost ideal bootstrap network.