Design of a Bulk-Driven High-Gain OTA Using Positive Feedback

In this paper, a new high-gain operational transconductance amplifier (OTA) circuit is designed. The proposed circuit uses bulk-driven technique to reduce the required supply voltage while gain-boosting as well as positive feedback techniques are used to increase the gain of the circuit and compensate the gain reduction effect due to the use of bulk-driven transistors. The performance of the proposed circuit is simulated using 180-nm CMOS technology parameters and is optimized using an optimization algorithm for the main purpose of minimizing the power consumption of the circuit. Simulated performance of the proposed circuit for 1.2 V DC supply voltage shows 94.8 dB gain, 203-MHz bandwidth, and slew-rate of 365-V/µS while occupying die area of 1360 µm 2 . However, the proposed circuit is also designed for a low-voltage scenario with 0.75 V DC supply voltage that results in 73.7 dB gain, 131-MHz bandwidth, and slew-rate of 149-V/µS.