BUCK3 & 4 of PMIC does not output when used with i.MX 8X Dual

[JK_Cha]

Hi NXP PMIC champs

We have an issue regarding PF8100 PMIC when supplying i.MX 8X. 

BUCK3 and 4 does not output upon Power On Reset even though other ports works normally.

And the other ports are output, but the power is dropped (about 5 ms) at a certain interval (300 ms) and then returned 

Can you please give us any guidance to fiugure out problematic area?

Thanks.

Regards, 

James

[JK_Cha]

Hi David.

Thanks for your kind reply.

Is it possible to configure PMIC with SCFW porting kit? e.g. imx-scfw-porting-kit-1.10.0.tar.gz

Thanks.

Regards, 

Jack

[diazmarin09]

Hello James,

I am pleased to contact you again.

I do assume that it is possible. I am not familiar with such a tool, but you can find more information at the following link:

System Controller Firmware 101 - Getting started

As mentioned before, you may configure the registers from the table above.

I hope this information helps.

Regards,

David

[JK_Cha]

Hi David

Thanks for your quick reply.

As you found the part applied is MC33PF8100FJES.  

The board design followed the EVM Kit. We didn't expect this happen. 

Can you please let me know how to enable SW3 and SW4 after power on? Using I2C command write?

Thanks.

Regards, 

James

[diazmarin09]

Hello James,

Thank you for using the NXP communities.

You are correct, you can enable such regulators by I2C commands after the power on.

The following registers are involved on the BUCK regulators behavior. Please find further information at the datasheet (chapter 15.4).

Please let me know if you have any further question about the device configuration.

Regards,

David

[diazmarin09]

Hello James,

I hope all is great with you.

Based on the schematic shared, you are using the MC33PF8100FJES device, I mean, the FJ configuration.

Please note that the SW3 and SW4 are OFF by default using this configuration.  

Could you please confirm?

Have you tried to turn on such regulators after the power on?

Regards,

David