NCP1081SPCGEVB【PDF 1/2 页】EVAL BOARD FOR NCP1081SPCG

Test Procedure for the NCP1081SPCGEVB Evaluation Board

Board connectors

Operational description

Normal operation

The NCP1081SPCEVB implements a PoE power splitter. A splitter splits the power from the

data on a PoE enabled network.

When the board operates without faults, the output connector should show a regulated output

voltage of 12V and Ethernet traffic should be passed from J4 to J1.

Fault management

The NCP1081 silicon has a built in thermal protection. If the temperature is too high, the

DC/DC will stop operation and output voltage drops to zero. As soon as the silicon cools down,

the DC/DC starts to operate again. When there’s a heat issue on the board, the output voltage

will slowly oscillate between 0 and 12V.

None of the external components are protected. Most vulnerable components are the switching

MOSFET and secondary rectifying diode. On failure of the MOSFET, the output voltage will

remain zero and the silicon will likely enter thermal protection. The above mentioned oscillation

will not be visible. When the secondary diode breaks down, the output voltage will be zero, or

some noisy level, lower than 12V.

Required test equipment

1. 30 PoE PSE (Power Source Equipment) equipment (Phihong POE30U, Farnell 1266818 )

or 57V,30W lab supply with Ethernet and power mixing board.

2. Oscilloscope

3. 30W load: 5Ohm Rheostat (Farnell 1129931) or 4.8Ohm resistor or programmable

current sink.

4. 2 CAT5, UTP Ethernet cables with RJ45 connectors.

Test Procedure:

1. Zero load, output voltage check.

Connect a scope to the output power solder contacts and set to the scope to the voltage range that

allows measurement of 12V DC.

8/26/2009

-1-

www.onsemi.com

发布紧急采购，3分钟左右您将得到回复。

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购