MP2624: Shutdown by I2C


I have the board powered by battery only. I want to shutdown the system cutting the battery voltage to the loads.
Using the DISC pin it runs correctly: >8 seconds DISC low to power off, then >0,5 sec to power-on.

I want also to shutdown by Software, that is writing 1 to REG07 Bit[5]. When I push the button for >0,5 sec I am not enable any more to power up, while the behaviour should be the same as the previous hardware mode.
Where am I wrong?

Thank you

Hi luca.vallone85,

Thanks for posting on the MPSNow Forum.
You cannot combine the DISC and REG07 function. Once you write 1 to REG07 Bit[5], the FET turns off. You cannot turn it back on using the DISC pin. You can only turn the FET back on by writing 0 to REG07 Bit[5].


Thanks for your reply. So, I cannot switch off the power to the load by software since I cannot restore by push button on DISC pin. The only way is by DISC pin when I have system powered by battery only?

If you write 1 to register 07 to turn the FET off, the datasheet states you have to write 0 to that register to turn the FET on again. You cannot use the DISC pin to turn the FET on.