An Overview of Negative Feedback Compensation Techniques for Operational Transconductance Amplifiers

Numerous compensation techniques are currently presented for ensuring the stability of CMOS operational transconductance amplifiers, from the Classical Miller compensation method of pole splitting using capacitors, to employing a nulling resistor, current buffer, up to nested Miller Compensation and its variants. Moreover, various other tactics of compensation like cascoding, pole zero cancellation and inserting the direct feedforward path into the circuit are suggested by many researchers. However, designers have no results on the frequency performance realizable that allow to deliberately choosing the best methodology to meet the prescribed specifications competently. In this paper, a comparison among various negative feedback compensation methods is carried out by analyzing compromise between gain, bandwidth, phase margin, slew rate and power utility for conventional CMOS technologies and two beyond CMOS technologies like FinFET and CNFET.