Analog Devices, Inc.
Predicting Failures in Feedback Network of Power Supplies Using a Secondary Servo Loop

Abstract:

A device to predict failure in a power supply includes a converter circuit configured to generate a regulated output voltage. The device additionally includes a first feedback circuit to generate a first feedback voltage proportional to the regulated output voltage and a second feedback circuit to generate a second feedback voltage based on the regulated output voltage. The second feedback circuit includes a voltage sampling circuit to detect the regulated output voltage, a correction circuit to generate a correction signal responsive to a voltage difference between the regulated output voltage and a specified output voltage, a reference circuit to obtain a specified correction signal to apply to the power supply, a comparator circuit to determine whether a difference between the generated correction signal and the specified correction signal exceeds a threshold signal value, and an alerting circuit to generate an alert signal responsive to the determination.