Embodiments of voltage regulators and methods for operating a voltage regulator are described. In one embodiment, a voltage regulator includes a power stage configured to convert an input direct current (DC) voltage into an output DC voltage, a driver device configured to drive the power stage, a timer configured to generate a constant on-time signal, a ripple generation device configured to generate a ripple signal, a comparator configured to perform voltage comparison in response to the ripple signal to generate an input to the timer, and a controller configured to generate a drive signal for the driver device in response to an inductor peak current in the voltage regulator and the constant on-time signal. Other embodiments are also described.