Low-voltage bulk-driven input stage with improved transconductance

摘要

A low-voltage input stage constructed from bulk-driven PMOS transistors is proposed in this paper. It is based on a partial positive feedback and offers significant improvement of both input transconductance and noise performance compared with those achieved by the corresponding already published bulk-driven structures. The proposed input stage offers also extended input common-mode range under low supply voltage in relevant to a gate-driven differential pair. A differential amplifier based on the proposed input stage is also designed, which includes an auxiliary amplifier for the output common-mode voltage stabilization and a latch-up protection circuitry. Both input stage and amplifier circuits were implemented with 1V supply voltage using standard 0.35 urn CMOS process, and their performance evaluation gave very promising results.