Patent ID: 8542468

Claim:
A switched mode power supply, comprising: a transformer having a primary winding and a secondary winding magnetically coupled to the primary winding, the secondary winding configured to provide an output; and an integrated circuit regulator coupled to the transformer, the integrated circuit regulator including: switching regulator logic coupled to receive a feedback signal representative of the output, the switching regulator logic to generate a switching signal in response to the feedback signal to control power delivered to the output; a counter coupled to receive the feedback signal, wherein the feedback signal periodically cycles between a first state and a second state when the switched mode power supply operates normally and wherein an output of the counter indicates an auto-restart mode of the regulator in response to the feedback signal remaining in the first state for a predetermined count due to a fault condition; and a switching transistor coupled to the primary winding of the transformer and coupled to be turned on and off in response to the switching signal when the output of the counter does not indicate the auto-restart mode, the switching transistor further coupled to be disabled when the output of the counter indicates the auto-restart mode.