Enhanced active-feedback frequency compensation with on-chip-capacitor reduction feature for amplifiers with large capacitive load

摘要

A large capacitive load amplifier with enhanced active-feedback frequency compensation is proposed in this paper. The enhancement is achieved through using a wide-bandwidth scalar circuit to increase the transconductance of the output stage so that the overall bandwidth of the amplifier can be extended considerably. Implemented in a standard CMOS 130-nm technology, with a supply of 0.7V and consuming 27A of current, the amplifier drives a load capacitor of 15nF. No on-chip resistor is needed; only a 0.91-pF compensation capacitor is used to maintain stability. The achieved gain-bandwidth product and phase margin are 1.28MHz and 66.9 degrees, respectively. Moreover, the slew rate is 0.263V/s. The active chip area is 0.0056mm(2). Copyright (c) 2017 John Wiley & Sons, Ltd.