Input common-mode adapter using multiple-input floating-gate devices

Abstract

A new common-mode (CM) feedback circuit for differential amplifiers that uses floating-gate devices is demonstrated. The circuit, which consists of a floating-gate CM voltage detector and a two-stage amplifier, generates a CM correction voltage to stabilise the floating-gate voltage of a differential amplifier against the input CM voltage. The proposed method achieves a rail-to-rail CM swing and a transconductance that is independent of the input CM voltage.