turn off the power supply of PMIC output

[sean_xiao1]

Dear all,

when the device is idle，I wants to shut down imx8QXP by turning off the power supply of PMIC output . At this time, the peripheral equipment(for example, swtich and 4G/5G module, etc.) is still in the live state.

Does imx8QXP pin have electricity at this time?If the pmic is turned on again and the CPU is rebooted, will system startup be affected?

  Thanks!

[gusarambula]

Hello Sean Xiao,

Are you referring to a custom board? There are a couple of things to keep in mind regarding power supplies when powering up and powering down. These can be found on the i.MX8QXP Datasheet.

https://www.nxp.com/docs/en/data-sheet/IMX8QXPAEC.pdf

If you are using the i.MX 8QuadXPlus MEK? The schematics for this board can be downloaded on the link below. This may help to understand how the power up is handled.

https://www.nxp.com/downloads/en/software/i.MX8QXPDF.zip

As mentioned on the datasheet, some power groups need to be powered off in certain order. And group zero should be the last to be powered down.

When powering up you would need to be careful if you will have modules powered on while the i.MX8 is powered down as there may be current leakage to say the least. Power up should be as listed on the datasheet.

One alternative if you need the i.MX8 to consume less power when other modules are still active would be using one of the available low power modes.

I hope this information helps!
Regards,