High-Gain and Fast-Setting OTA for high Speed and high Resolution ADC

A two stage Gainboost OTA for high speed and high resolution Pipeline ADC is presented. Negative impedance compensation and Negative capacitance compensation are used to promote OTA DC gain and closeloop feedback coefficient; High resistances are in series connection between substrate of pmos and supply to decrease the output parasitic capacitor. Meanwhile, reset switches are in parallel with high resistances to avoid voltage drift.The simulation of proposed circuit results in 83dB Loop DC gain, 4.3GHz Closeloop Bandwidth, and 63 degree phase margin.