Low power SC CMFB folded cascode OTA optimization

摘要

This paper describes a design of a switched capacitor common mode feedback (SC CMFB) folded cascode operational transconductance amplifier for low power and high-speed sigma-delta modulators. An algorithmic driven methodology is developed ending to the optimal transistor geometries. Using a 0.35μm CMOS process, the OTA circuit has been designed to achieve 82.94dB DC gain, 526MHz unity-gain frequency, 560V/μs slew rate with 1.8V power supply voltage and a power consumption of only 1.19mW. The simulated OTA circuit has been applied in a SC integrator to illustrate the versatility of the circuit.