An offset compensated class-AB sample-and-hold amplifier using two sampling capacitors

Abstract

Abstract:A new circuit topology of an offset compensated class-AB sample-and-hold (S/H) amplifier using two sampling capacitors is described. Conventional class-AB S/H amplifiers have high power efficiency, but suffer from offset deviations of the internal amplifier. The proposed class-AB S/H amplifier is free from the offset deviation of the internal amplifier, while achieving high power efficiency comparable to conventional class-AB S/H amplifiers. Simulation results show that systematic offset of the proposed S/H amplifier is comparable to that of an offset-compensated class-A S/H amplifier and has faster settling speed than that of the class-A type amplifier.