A voltage supply circuit having variable drive strength can optionally be used to provide improved phase margin in an integrated circuit. A bandgap circuit drives an operational amplifier, with the second input of the operational amplifier being a regulated voltage node. The operational amplifier drives multiple pull-ups in a pull-up network coupled to the regulated voltage node, of which the different pull-ups can be separately enabled to control the effective channel width of the pull-up network. In some embodiments, a control circuit (e.g., one or two additional operational amplifiers driving a counter) accepts the output of the operational amplifier as an input signal and provides multiple enable signals to the pull-up network.