Other Parts Discussed in Thread: TPS2493
The LM5050 datasheet says that it is designed to regulate the voltage across the MOSFET to 22mV if possible. Otherwise it will saturate the gate voltage to about 12V.
When using a low Rds MOSFET (1m Ohm), it seems the LM5050 will be holding the MOSFET Vds at 22mV for currents less than 22A, when the MOSFET could achieve lower Vds if the gate was driven harder. At a nominal current of 10A (with Rds = 1m Ohm), forcing Vds=22mV creates about 0.22W of power dissipation, when it may be as low at 0.1W if the gate was driven hard enough.
In the example circuit shown here (TPS2493 followed by an LM5050) are there any drawbacks to moving the connection of the "IN" pin of the LM5050 directly to the source voltage, so that the drop across the 1m Ohm sense resistor and the hot-swap MOSFET are combined in to the 22mV that the LM5050 is trying to servo?
Thanks for any insights,
Will
