Design of high gain and high bandwidth operational transconductance amplifier (OTA)

A novel operational transconductance amplifier (OTA) having high gain and high bandwidth for high-speed analog communication techniques and precision filtering is designed in this paper. The designed OTA uses beta-multiplier-based current biasing scheme with folded cascode amplifier scheme in order to improve the small signal models and the DC gain of circuit. The OTA design was carried out using TSMC 65 nm CMOS technology using Cadence Virtuoso tool with 1 V supply voltage and 10 pf capacitive load. The output DC gain was found to be approximately 75.3 dB. In addition, the unity gain frequency for the designed OTA was found to be around 200 MHz. Superior common mode rejection ratio, power supply rejection ratio and slew rates along with compact chip area and low power are other salient features of the designed OTA. The designed OTA can be employed in order to design high performance analog circuits like data converters, phase-locked loops, etc.