An Amplifier for High Speed High Accuracy Pipelined ADC

An amplifier with novel configuration is presented.It consists of two parts:a transconductance amplifier and a transresistance amplifier formed by resistor feedback.The combination of these two amplifier forms a voltage amplifier with low output impedance,and the pole at the output node is hardly affected by the loading capacitor.It is used as preamplifier to drive a single stage amplifier and thus a two stage operational amplifier is implemented.Simulation results show that more than 1GHz gain bandwidth product is achieved(4-pfload) with a power consumption of 25mW only.Transient simulation indicates a settling time of less than 10ns for 0.01% accuracy with a close loop gain of 8.This two stage operational amplifier is appropriate to be used in high speed high accuracy pipelined analog to digital converters.