Reverse Current Protection of MCP5515

Hi,
We are evaluating MP5515 for one of our application.
In MP5515 datasheet, There is a section on RCP on page 19,
“The ISOFET circuit applies reverse-current protection (RCP) when energy is released from the storage capacitors to VB. Typically, a
250mA reverse current from VB to VIN shuts down the ISOFET.”

I have few doubts here,

  1. Unless there is a Reverse current of 250mA flowing from VB to VIN, whether ISOFET won’t be OFF, i.e. the RCP functionality won’t kick in.
    Because, if it is the case, then I need to allow 250mA of current on VIN side, for RCP to kick in.

  2. ISOFET looks like Back-to-Back MOSFET so, when it is OFF there won’t be Forward/Reverse current flow. Why MP5515 will wait until it see 250mA Back current flow to Turn OFF the ISOFET. Am i missing something on this?

Thanks.

Can anybody check this question and answer it.

Well if the FET is ON but no current is flowing through it, what exactly is the problem?
I tend to agree on some level, if they are discharging the storage cap they have enough reason already to turn prevent reverse current into Vin. So it would seem a harmless move to disable the input fet in the power fail condition. What if you had a 200mA load on the Vin? That would shorten the backup time for no good reason. In the end that can all be compensated for with a larger storage cap.