Discharge Circuit for EXT_1V8 on i.MX8QXP MEK can not work well

[question2click6]

Dear Sir/Madam,

I think the discharge circuit on i.MX8QXP MEK board can not work well if VCC12V0 power down, because:

 if 12V power down will lead VCC_EXT_3V3 at low level, so Q14 will remain at closed state.

please check on this, thank you!

Wenwen

[Rita_Wang]

Hi Wen,

  There are too many caps on the net of VCC_EXT_3V3, the power down sequence of the power rail is later, it can make Q14 open and realize discharged. The circuit is verified on our EVK board.

Hope this can do help for you.

Have a nice day

Rita