An IC controller for USB Type-C device includes an error amplifier (EA), which includes an EA output coupled to a PWM comparator of a buck-boost converter; a first transconductance amplifier to adjust a current at the EA output, the first transconductance amplifier operating in a constant voltage mode; and a second transconductance amplifier to adjust the current at the EA output, the second transconductance amplifier operating in a constant current mode. A first set of programmable registers is to store a first set of increasingly higher transconductance values. A second set of programmable registers is to store a second set of increasingly higher transconductance values. Control logic is to: cause the first transconductance amplifier to operate while sequentially using transconductance values stored in the first set of programmable registers; and cause the second transconductance amplifier to operate while sequentially using transconductance values stored in the second set of programmable registers.