The link to the schematic is
My requirement is to enable the regulator when BATT_12V (12V) is present AND/OR GPIO from MCU is HIGH (3.3V). Disable only when BATT_12V not present and GPIO is Low (0V).
Max input to Enable pin is 6V. Leaving Enable pin floating or > 1.6V enables the regulator.
1) Will the above schematic work?Also note from the schematic that the GPIO from MCU will turn Low to switch off the power to itself by disabling the regulator. Once power down the MCU can only be powered up by applying BATT_12V power.
2) Will there be any instability when the MCU turns GPIO Low and regulator is disabled cutting off supply to MCU? How to add little delay (say 200 ms ) to bring Enable pin Low after the GPIO becomes Low to allow MCU to shutdown properly?3) Will R5 keep Enable pin at Ground (prevent floating) when BATT_12V not present and GPIO is Low?
4) Any potential issues with this design?Thanks
-mj