onsemi PoE DC/DC Converter Evaluation Board Power Over Ethernet (POE) for NCP1031DR2G for PoE DC-DC Converter

A solution to one aspect of Power Over Ethernet (POE) is presented here utilizing the ON Semiconductor NCP1031 series of monolithic, high voltage switching regulators with internal MOSFET. The NCP1031POE evaluation board is an inexpensive, high efficiency, 6.5 W, 5.0 V DC output power supply along with the associated input circuitry for responding to POE detection and classification protocol. The input is 48 Vdc nominal and the output is 5 Vdc at 1.3 A maximum. There is additional input circuitry that responds to Ethernet protocol defined as 'Signature' and 'Classification' detection. Signature just indicates that the power supply does exist and classification allows the upstream Power Sourcing Equipment (PSE) to determine the rated power level of the supply or Powered Device (PD). Both of these detection modes are performed at low input voltages in which the main converter does not operate. The converter will only come on with Vin above 35 Vdc.