Circuit and method for protecting a switching power supply from a fault condition

A circuit, comprising:

• a switching regulator generating a drive signal in response to a feedback signal;
• and
• a timer circuit coupled for receiving the feedback signal to reset the timer circuit if the feedback signal is received during a timer period, wherein the timer circuit generates a fault signal to disable the drive signal if not reset during the timer period.

A method of detecting a fault condition in a switching regulator which operates in response to a feedback signal to provide a drive signal, comprising the steps of:

• monitoring the feedback signal;
• and
• detecting the fault condition if less than a number of feedback signals are received during a timer period.

A method of operating a regulator circuit, comprising the steps of:

• generating a drive signal in response to a feedback signal;
• and
• disabling the drive signal if less than a number of feedback signals are received in a period of time.