A circuit configuration for a CMOS buffer amplifier is described. The circuit, which is an enhancement of a previously reported buffer amplifier, features a large output voltage swing and a well-controlled quiescent current. A buffer amplifier of this type has been implemented in a 1.5- mu m CMOS technology. The prototype occupies an area of 275 mil/sup 2/. It works with a 5-V supply and can drive more than 4.2 V (peak to peak) in to 300 Omega with a total harmonic distortion of less than 0.025%.<>