MP8005 – IEEE 802.3af PoE POWERED DEVICE CONTROLLER

MP8005 Rev. 1.0

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10

9/26/2013

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is very important in that it prevents cross

conduction of the switching MOSFETS that either

severely reduces efficiency or even worse, a

switching MOSFET failure.

The output drive levels of the main and

synchronous gate are in the hundreds of mA

through a 0 to 10V voltage potential. A “normal”

threshold MOSFET (Vth typ. 3.5V) having low

gate charge (less than 10 nano-Coulombs @

10V drive) is recommended.

The nominal range of the ISENSE pin is set to a

maximum of 200mV but should be designed such

that 100mV across the sense resistor provides

the maximum current that is expected for the

nominal

load.

This

will

provide

enough

“headroom” for typical applications.