A CMOS wideband amplifier with 800 MHz gain-bandwidth

A fully differential unity-gain stable CMOS wideband operational amplifier, realized in a standard 1.2- mu m CMOS process, is presented. The amplifier uses a capacitive feedforward technique to avoid p-channel transistors in the signal path. With a well-considered transistor sizing, the parasitic poles of the amplifier are shifted to the highest possible frequencies that can be reached with this 1.2- mu m technology. In this way, a gain-bandwidth product of 800 MHz and a phase margin of 53 degrees can be obtained.<<ETX>>