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How to choose the MOSFET for ADM1175-1

Hello,

what is the criteria for choosing the MOSFET switch to be used with the ADM1175-1?

From the data sheet on page 14, in a normal hot-swap event, the "FET Gate is charged up with a 12.5uA current source", then the "FET is controlled to keep the sense voltage at 100mV". From data sheet page 3, Vgate(max and min) depends on Vcc, which in my case will be changing overtime because it is a large 12.5 Volt battery.

I was thinking to use the Si1070X MOSFET from Vishay. How do I make sure that the Si1070X will work well with the  ADM1175-1 ?

Thank you,

Claudio

  • Hello,

    The Vgate spec does indeed change with VIN but it usually is not a concern for many modern MOSFETs especially logic level MOSFETs as their Vgate threshold is low. The main concern when picking MOSFETs for Hotswap applications is their SOA (Safe operating Area). Depending on your applications power requirements and the load capacitance downstream, the power dissipation in the MOSFET during turn on events and/or fault events could exceed the limits of the MOSFET. The SOA curve of SI1070x is provided on page 4. Please check with your applications power levels to see if it can dissipate the required amount of power.

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