A burst-mode controller for a DC-DC converter includes an output module configured to provide a switch control signal to the DC-DC converter. The switch control signal includes a plurality of burst windows, each burst window corresponding to a period of a fixed-frequency burst clock and having a number of switching cycles. The burst-mode controller includes an on-time-control-module configured to receive a compensation signal based on the output voltage of the DC-DC converter, and set an on-time of the switching cycles of the switch control signal based on the compensation signal. The burst-mode controller also includes a burst-control-module configured to regulate the on-time of the switching cycles of the switch control signal by setting the number of switching cycles for each burst window of the switch control signal.