A Novel Active Feedback Frequency Compensation Scheme for Two-Stage OTA

Abstract

A novel active feedback frequency compensation scheme is presented in this work. Based on the proposed technique, an amplifier with two main poles in its frequency bandwidth can be easily compensated by introducing a pole-zero pair in a local feedback. The proposed method is mathematically analyzed and then based on the derived formulations, a design procedure is established. The capability of the proposed technique is examined considering a well-known two-stage amplifier, considering just a trivial modification on its input stage. To gain an analogous and fair insight, the performance of the proposed structure is compared with that is of the optimally designed miller-compensated two-stage amplifier. The post-layout simulations are accomplished with TSMC 180nm CMOS standard technology. The Spectre post-layout simulations show that the proposed structure outperforms the traditional structure in terms of power consumption and gain bandwidth product. The robustness of the design is checked with Monte Carlo simulations.

Keywords

• Low Voltage
• Low Power
• Frequency Compensation
• Operational Amplifier.