Design of a Bulk Driven Gain Boosting Technique Operational Amplifier for Low Power and High Swing Applications
Sandeep Kakde, Rajesh Thakare, Shailesh Kamble, Manoj Patil and Pavitha U S
In this paper, a Bulk Driven Gain Boosting (BDGB) technique has been analyzed which is further employed in the design of a novel operational amplifier to enhance the gain and at the same time, a nested compensation technique is also used to improve the bandwidth without consuming extra power. The proposed operational amplifier circuit has been designed in sub threshold region and is biased with very less current at the first stage; an extra biasing circuit with gate to drain connected transistors is also designed to bias the last stage. The proposed configuration achieves open loop gain of 70dB, CMRR of 144dB, PSRR of 70dB and the unity gain bandwidth of 11MHz at 5pF load capacitance. The output swing is more than 650mV at 0.8V supply voltage consuming only 2.5μW static power. The gain/swing performance of the proposed low-voltage OPAMP would be therefore good enough not to require another amplifying stage in many high-speed, high swing and low-power applications.
Keywords: Ultra low voltage, ultra low power, op-amp, sub-threshold region, bulk driven gain boosting