Single-miller all-passive compensation network for three-stage OTAs

A compensation technique for low-power high-capacitive-load three-stage operational transconductance amplifiers is presented in this paper. The compensation network is made of passive components only and, as an example, the proposed technique was used to design a three-stage amplifier in a standard CMOS 65-nm technology. The amplifier achieves a 2.64-MHz gain-bandwidth product when driving a 1-nF capacitance by consuming only 155 μW from a 2.5-V supply. Simulation results are found in good agreement with theoretical analysis and show an improvement in both small-signal and large-signal amplifier performance over previously reported solutions.