Patent ID: 8207714

Claim:
A voltage regulator having a synchronous mode and an asynchronous mode, the voltage regulator comprising: an input pin; a switch node; a ground pin; a high-side switch to electrically connect the switch node to the input pin only if on; a low-side switch to electrically connect the switch node to the ground pin only if on; an oscillator to generate a signal having a switching frequency; a feedback pin having a feedback voltage; and a controller to generate a pulse-width-modulated signal in response to the feedback voltage and a reference voltage, the pulse-width-modulated signal having a frequency equal to the switching frequency; the controller, when the voltage regulator is in the synchronous mode, to switch on and off the high-side switch and the low-side switch in response to the pulse-width-modulated signal; and the controller, when the voltage regulator is in the asynchronous mode, to keep the low-side switch off and to switch the high-side switch on for a time interval in response to the feedback voltage and the reference voltage satisfying an ordered relationship, and provided the switching of the high-side switch has an effective frequency less than the switching frequency.