Patent ID: 8598899
Filing Date: 2013-12-03
Classification: H02H

Abstract:
1. A built-in test circuit for an overvoltage protection circuit that provides transient overvoltage protection to electrical components connected to a control line, the overvoltage protection circuit includes a blocking diode connected in series with a transient voltage suppression (TVS) device via a first node and further includes a reference voltage for biasing the first node at a voltage sufficient to reverse bias the blocking diode during normal operations, the built-in test circuit comprising: a resistor connected to the first voltage node; a switch connected in series with the resistor and selectively turned On and Off to test the overvoltage protection circuit; and a controller that monitors a first voltage at the first node and a second voltage on the control line while the switch is On and while the switch is Off, and in response to the monitored first and second voltages detects the presence of faults in the overvoltage protection circuit.