Patent ID: 7511388

Claim:
A powered device comprising: at least one power supply input responsive to an external power source; a diode bridge having an input to receive the at least one power supply input; and a power loss detector having an input responsive to the at least one power supply input, the power loss detector to detect a power loss event, and to initiate a power shutdown to turn off power to at least one circuit coupled to the diode bridge in response to detection of the power loss event, the power loss detector comprising: at least one blocking diode responsive to the at least one power supply input; a zener diode circuit including an input coupled to the at least one blocking diode and including an output, the zener diode circuit having a breakdown voltage characteristic that defines a voltage level related to the power loss event; and a comparator coupled to the output of the zener diode circuit, the comparator to generate an output signal related to a voltage level of the at least one power supply input.