Other Parts Discussed in Thread: TPS22916
Dear,
I have a question as in https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1104591/bq21061-reverse-voltage-to-the-ldo-of-bq21061?tisearch=e2e-sitesearch&keymatch=bq21061#, i.e. I need to connect an external voltage (~3V) to the OUTPUT of the LDO(LS/LDO pin) and not the input to program the MCU. Reading the answers to this previous post I understand that possible damage could happen if an external voltage was applied to the LDO output when no input was applied since the body diode of the mosfet between VINLS and LDO conducts and this current path is not a normal behaviour.
To solve this issue I would like to know if it is possible to connect a schottky diode between VINLS and LDO with the anode connected to the LS/LDO pin (in our configuration VINLS is connected to PMID). In this manner when we will apply a voltage to the LS/LDO pin the schottky diode will conduct and bypass the electronic components inside BQ21061 between VINLS and LS/LDO pins avoiding possible damage of this electronics. During normal behavior the schottky diode will not conduct since the VINLS pin will be greater than LDO output.
Please not that, in our application, we cannot insert a schottky diode in series with LS/LDO output to prevent current to flow in reverse direction since at power up the BQ21061 has the LS/LDO output by default to 1.8V and the voltage drop with this schottky series diode will lead to a voltage less than 1.7V that is the minimum voltage for power up our microcontroller.
Thanks
Francesco