Patent ID: 9484824
Filing Date: 2016-11-01
CPC Classification: H02M

Claim Text:
1. An on/off controller device for a switched mode power supply, the on/off controller device comprising: a control circuit to generate a control signal to switch a power switch between an on state and an off state and thereby transfer energy from a primary side to a secondary side of the switched mode power supply; and a comparator coupled to generate an enable signal that enables and disables the switching of the power switch by the control circuit, the comparator to compare a feedback signal that is representative of an output level of the switched mode power supply with a variable threshold and switch the enable signal between enabling and disabling the switching of the power switch in response to the feedback signal crossing the variable threshold, wherein the variable threshold is modulated to increase a fundamental frequency of the switching of the power switch by the control circuit, wherein the variable threshold is modulated with a fixed amplitude pulse that is combined with a second threshold to modulate the variable threshold between a first higher value and a second lower value.