Abstract: A circuit for controlling the bias current in a differential amplifier is disclosed. A differential amplifier comprising complementary differential input transistor pairs includes variable bias current sources to provide bias currents to the differential input pairs. The variable bias current sources are coupled to an input current control unit that includes one or more programmable switches to vary the amount of bias current supplied to the differential input pairs. The slew rate, differential gain, and common mode input range of the differential amplifier may be varied by adjusting the bias currents to the differential input pairs. A cascode circuit is coupled between the differential input pairs and their respective load circuits to extend the common mode input range to the supply voltage rail values.