Abstract: An operational transconductance-amplifier (OTA) is basically designed for low voltage and low power applications. Bulk driven technique is widely used for the low supply voltage applications in the analog circuits, but it has another drawbacks such as low gain , low slew rate , and low bandwidth. In this paper, cascade technique is used the overcome the problem of the low gain, slew rate and low bandwidth. The proposed bulk driven three stage OTA is implemented with the use of cascoding technique. The 65nm CMOS technology is used for the designing of the proposed three stage OTA circuit. The measured results of the simulation shows that the proposed three stage OTA circuit requires the power consumption of 124.3µW and slew rate of 77.20 V/us. It also improves the gain, bandwidth of the bulk driven OTA.

Keywords: Moore’s Law, CMOS technology, Cascoding technique, OTA.