A power supply margin controller may alter the voltage of a control signal used to control the output voltage of a power supply. The controller may include a digital-to-analog converter having an input and an output, and a comparator having a first input coupled to receive the control signal, a second input coupled to the output of the digital-to-analog converter, and an output. The controller may include a processing system configured to deliver data to the input of the digital-to-analog converter based on the output from the comparator that causes signals at the inputs to the comparator to be substantially equal.