Novel high-frequency track-and-hold stages with offset and gain compensation

Two novel fully-differential track-and-hold stages are proposed. The gain of the stages does not depend on capacitor matching, and they use a predictive correlated-double-sampling scheme to reduce the effects of op-amp offset and finite dc gain. Due to these properties, they are well suited for the construction of a fully-differential sample-and-hold stage using a ping-pong approach. Simulations indicate that these circuits are capable of high-speed and high-accuracy operation without requiring high-quality components.