Low-voltage differential amplifier

Abstract

A low-voltage differential amplifier constructed by bulk-driven PMOS transistors is proposed in this paper. A local positive feedback is utilized that boosts the input transconductance and improve the noise performance. The input common-mode range is also compared to the gate-driven counterpart. A 5th order Chebyshev active RC filter with 500 kHz cut-off frequency and 1dB ripple is built based on the proposed amplifier. All circuits were implemented with 1V supply voltage using standard 0.35um CMOS process presenting very promising performances.