0.9 V rail-to-rail constant g_m CMOS amplifier input stage

摘要

Presented is a 0.9 V rail-to-rail constant g_m CMOS amplifier input stage consisting of complementary differential pairs and a g_m control circuit. The g_m control circuit eliminates the g_m dead zone, which occurs in the conventional rail-to-rail amplifier with ultra-low supply voltages. The proposed amplifier input stage has a constant g_m that varies by ± 2.3% for rail-to-rail input common-mode levels. To verify the proposed amplifier design, an experimental prototype operational amplifier is also implemented using 0.35 μm standard CMOS technology.