Rail-to-Rail Ⅴ-Ⅰ Conversion Using a Pair of Single Channel MOSFETs Operating in Plural Regions

摘要

A novel linear voltage-to-current conversion circuit for a rail-to-rail input voltage is proposed in this paper. A pair of MOSFETs operating in plural regions are used for the conversion and a difference of their drain currents is used as an output current. The two MOSFETs work complemetarily and realize a rail-to-rail input range. The output current is linear in any input voltage from the ground potential to a power-supply voltage. Two types of circuit configurations which realize the proposed concept are given. From the viewpoint of area efficiency and linearity the proposed circuit is superior to a voltage-to-current converter previously proposed by the authors, which uses a set of three MOSFETs to achieve a rail-to-rail voltage-to-current conversion. The operation principle of the proposed method is confirmed through HSPICE simulations.