A reference signal generator for generating an output reference signal having a target duty cycle. The reference signal generator comprises a sawtooth generator for receiving an input reference signal having a reference frequency and generating a sawtooth waveform having the reference frequency. Comparison circuitry compares the sawtooth waveform to a reference voltage and generates the output reference signal. The output reference signal is Logic 1 when the sawtooth waveform is greater than the reference voltage and is Logic 0 when the sawtooth waveform is less than the reference voltage. Feedback circuitry determines a duty cycle of the output reference signal by comparing a first time period when the output reference signal is Logic 1 to a second time period when the output reference signal is Logic 0. The feedback circuitry adjusts a value of the reference voltage to cause the output reference signal to achieve the target duty cycle.