Method and apparatus to limit maximum switch current in a switching power supply

摘要

Techniques are disclosed to limit the current in a switch of a switching power supply. An example switching regulator circuit includes a power switch to be coupled to an energy transfer element of a power supply. A controller to generate a drive signal is coupled to be received by the power switch to control the switching of the power switch. A short on time detector is included in the controller. The short on time detector is to detect an occurrence of a threshold number of one or more consecutive short on times of the switch. A frequency adjuster is also included in the controller and coupled to the short on time detector. The frequency adjuster is to adjust an oscillating frequency of an oscillator included in the controller in response to the short on time detector.