A CMOS operational amplifier with low impedance drive capability

A CMOS operational amplifier capable of delivering 160 mW of power to a 100 /spl Omega/ load while only dissipating 7 mW of quiescent power is described. The amplifier consists of three stages, the last of which is a transconductance output driver. The output stage is operated class B with less than 2 percent typical THD. A method of setting crossover by ratioing current mirror loads to parallel invertors is shown. Experimental results are presented showing various nominal operating characteristics.