A new high-frequency very low output-impedance CMOS buffer

A technique to increase the transconductance of the MOS transistor by employing current feedback is presented and applied to the design of a voltage follower. Simulation results show that the output impedance of the buffer is kept very low over a wide range of frequencies while the input impedance remains very high. At the same time this buffer configuration shows wide bandwidth of operation, ability to drive large capacitive loads without oscillation and with very good linearity. Finally an example of a CFOA (current feedback op amp) using this buffer is presented.