Switching mode power supply with a multi-mode controller

A method for controlling a switching mode power supply, comprising:

• regulating an output voltage of the switching mode power supply by switching a transformer on and off at a switching frequency;
• generating a feedback signal that varies in relation to a load coupled to the output voltage;
• controlling the switching frequency based on the feedback signal;
• and
• limiting a peak current through a primary winding of the transformer based on the feedback signal.

A multi-mode controller for a switching mode power supply that includes a transformer having a primary winding and a secondary winding to supply power to a load and a feedback circuit that generates a feedback signal that varies in relation to the load on the secondary winding, the multi-mode controller comprising;

• a switching circuit to be coupled to the primary winding to control current flow through the primary winding;
• a frequency control circuit to control a switching frequency of the switching circuit based on the feedback signal;
• and
• a current limiting circuit to limit current flow through the primary winding by causing the switching circuit to suspend current flow through the primary winding when the current reaches a peak current limit that is set based on the feedback signal.