A 1.2V 110-MHz-UGB differential class-AB amplifier in 65nm CMOS

A wideband, fully differential, 3-stage class-AB amplifier capable of operation at rates beyond 100 Mbps is described. Common-mode feedback is applied to increase output drive capability and reduce bias-dependent crossover distortion when operating in class-AB from a low supply voltage. Drawing 3.9mA from a nominal V
_DD
of 1.2V in 65nm CMOS, the 0.052mm
²
amplifier delivers 1.6V swing across a 50Ω load with THD+N of 82.6dB at 150kHz in the unity-gain configuration.