A power-efficient current-feedback instrumentation amplifier for precision bridge readout

摘要

A current-feedback instrumentation amplifier (CFIA) for precision bridge-readout intended for MEMs flow sensor is presented. The proposed CFIA is chopped to bring input-referred offset below 12μV and flicker-noise corner around 2mHz. Implemented in chartered 0.18μm CMOS process, the CFIA draws 250μA supply current and achieves a competitive noise efficiency factor (NEF) of 30.5. The low-power consumption is attributed to the g/I based design methodology adopted in designing the folded-cascode amplifiers while considering careful trade-offs between power, thermal noise and input-referred offset.