A 1.65V Indirect-Compensated Class-AB OTA for Low-Power Low-Voltage Applications

This work presents the design and simulation of an indirect compensated class-AB operational transconductance amplifier (OTA) suitable for low-power low-voltage applications. The designed OTA is made up of a two-stage amplifier that is stabilized using an indirect Miller compensation capacitor while a Class-AB modification used to enhance the slew rate of the overall amplifier. Self-cascode composite transistor were used to improve the amplifier DC gain. The designed OTA presents a DC gain, bandwidth, gain-bandwidth product, and phase margin of 79.6 dB, 79 Hz, 655 kHz, and 42°, respectively. Also, this OTA exhibits a slew rate of 0.371 V/μs, a power consumption of 1.32 μW, and a silicon area of 170.7 μm x 191.25 μm. A 0.50μm CMOS standard technology was used for simulation and layout purposes.