Texas Instruments Incorporated
OUT OF AUDIO SWITCHING FOR POWER SUPPLY

Abstract:

A power converter includes a watchdog circuit having an input adapted to be coupled to a pause signal of a switching power supply. The watchdog circuit is configured to provide a start signal at an output thereof based on the pause signal indicating that the power converter has stopped switching for a threshold duration that is less than an audible range. A pulse generator circuit has an input coupled to the output of the watchdog circuit and is configured to generate at least one pulse based on the start signal. A switch circuit has an input terminal adapted to be coupled to an input voltage and at least one other terminal adapted to be coupled to an inductor. The switch circuit is configured to provide negative current from an output of the power converter through the at least one other terminal based on the at least one pulse.