Rail-to-rail OTA using a pair of single channel type MOSFETs

This paper proposes a rail-to-rail operational transconductance amplifier (OTA). The OTA has an input stage which consists of a pair of two MOSFETs operating in plural operation regions. The MOSFETs work complementarily and realize a rail-to-rail input range. The input stage requires no matching of an n-channel type input circuit and a p-channel type input circuit unlike conventional rail-to-rail input stages because the input stage is realized by single channel type MOSFETs. The operation principle of the proposed OTA is confirmed through HSPICE simulation.