Disclosed are methods, devices, and systems to digitally control a duty cycle of a switching mode power supply. In one embodiment, a method comprises calculating a base duty cycle using a power management unit of a high-speed processing unit, calculating a dynamic offset duty cycle using the power management unit to apply a transfer function to a sampled feedback voltage signal, and adding the base duty cycle to the dynamic offset duty cycle to obtain a duty cycle of the switching mode power supply. A system comprises a switching mode power supply, a power management unit, a voltage sensor, and an analog to digital converter all embedded within a high-speed processing unit, and a pulse-width modulator coupled between the switching mode power supply and the high-speed processing unit to modulate the duty cycle of the switching mode power supply.