A controller for a DC to DC converter is configured to provide a PWM signal in a first state during a first time interval based on an input voltage less a voltage level representative of an output voltage of the DC to DC converter. The controller may provide the PWM signal in the first state based on the time it takes to charge an energy storage element of the controller to a predetermined level. The controller may also provide an estimator of a zero inductor current level in an associated inductor when the energy storage element is completely discharged. The controller may also be a digital controller that counts time pulses to provide the PWM signal. A DC to DC converter including such a controller and associated methods are also provided.