Design considerations on CMOS bulk-driven differential input stages

Design considerations regarding the DC behaviour of CMOS bulk-driven differential input stages are addressed in this paper. Unlike in conventional gate-driven circuits, the input terminal of a bulk-driven transistor consists of a pn junction, whose real behaviour is critical to determine the input performance of the overall circuit. In this work, the simulated and experimental performance of a bulk-driven differential pair are illustrated and compared in order to draw design hints. The conclusions drawn are applied to the design of a low-voltage bulk-driven voltage-to-current converter in 0.35-µm standard CMOS technology.