Disabling the gate would not have much value, other than testing, removing this pin would be OK.
If it turned off the FET it would be great, but as the drain-body diode is ever-present this would not be possible.
I can see no reason for this pin other than creating some extra heat. 65A gets really warm!
Hi Chris,
In redundant systems with resistive feeds, (or under light load in single supply systems), ORing controllers can oscillate.
o In light load systems the impact is usually limited to noise and layout issues.
o In multiple supply systems the impact can be more damaging. The oscillations heat up the FETs as they turn on and off, eventually causing SOA violations and failure.
- It is possible to use a detection circuit to sense such oscillations and shut off the FET to force current through another feed.
However I understand the OFF pin has limited use other than these conditions and as you had mentioned (to test the FET).
If there is a high current application and disabling the FET would be a useful feature, check out this TI design which uses the LM5069 + LM5050.
This offers ON/OFF control, current limiting, mosfet power dissipation protection, reverse current protection, reverse polarity protection, UV, OV, and more.
Thanks!
Alex
