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Method for a circuit and apparatus for detecting power loss and generating a dying-gasp message

IP.com Disclosure Number: IPCOM000008683D
Publication Date: 2002-Jul-02
Document File: 2 page(s) / 55K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a circuit and apparatus for detecting power loss and generating a dying-gasp message. Benefits include improved functionality.

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Method for a circuit and apparatus for detecting power loss and generating a dying-gasp message

Disclosed is a method for a circuit and apparatus for detecting power loss and generating a dying-gasp message. Benefits include improved functionality.

Description

              The disclosed method is a dying-gasp implementation can be broken down into two major functions:

§         Generation of an interrupt when a power-failure event occurs

§         A reservoir of power sufficient to send the dying-gasp message

              Interrupt detection is performed using a field-effect transistor to monitor the power-supply input level. When the input level drops below the gate level, power is quickly shut off. A positive edge, or rising edge interrupt, is generated, consuming virtually no power from the system.

              Storing the power reserve is accomplished by using a high-current schottkey diode in series between the incoming power source and any other regulation circuitry on the board. This removes the discharge path for the on-board capacitance in case of a power failure. A large amount of capacitance acts as a reservoir and enables power to remain present for some period of time. However, no bulk capacitance should reside in the power failure detection circuit.

              To support gateway platforms, the disclosed method can be implemented as in the schematic (see Figure 1).

Advantages

              Current power failure supervisory circuits can generate an interrupt based on regulated input voltage. With the disclosed method, power can remain presen...