BQ25628EVM: The PMID_GD waveform of power-down has a sudden jump.

Ryker She

Intellectual 2040 points

Part Number: BQ25628EVM

Hi,

I have found the PMID_GD waveform of power-down has a sudden jump. What reason cause this?

In BQ25628EVM, the PMID_GD is connected to GREN. Is the system pull-down PMID_GD automatically after system beginning to power-off? And why GREN doesn't be pulled-down by PMID_GD? Thanks.

Best regards,

Ryker

over 2 years ago

0 Garrett Kreger over 2 years ago

TI__Mastermind 27575 points

Hi Ryker,

We are checking and will get back to you.

Best Regards,

Garrett

0 Garrett Kreger over 2 years ago in reply to Garrett Kreger

TI__Mastermind 27575 points

Hi Ryker,

I am unable to observe the same phenomenon. In my testing with BQ25628EVM at power down once PMID_GD drops to GND it remains there. Can you provide more details for your test conditions such as VBUS, VBAT and if any load is connected at either SYS or PMID.

Regards,

Garrett

0 Ryker She over 2 years ago in reply to Garrett Kreger

TI__Intellectual 2040 points

Hi Garrett,

I tested with the VBUS=5V/ VBAT=3.2V/ ICHG=1A. And I can recur your phenomenon without load and battery.

Best Regards,

Ryker

0 Garrett Kreger over 2 years ago in reply to Ryker She

TI__Mastermind 27575 points

Hi Ryker,

Thank you for the additional information. I will look into this some more and get back to you next week.

Best Regards,

Garrett

0 Ryker She over 2 years ago in reply to Garrett Kreger

TI__Intellectual 2040 points

Hi Garrett,

Soft remind, have you took any conclusion of this questions?

Best Regards,

Ryker

0 Ning T over 2 years ago in reply to Ryker She

TI__Guru 54201 points

Hi Ryker,

Garrett is out of office currently. He will get back to you next week.

Thanks,

Ning.

0 Garrett Kreger over 2 years ago in reply to Ning T

TI__Mastermind 27575 points

Hi Ryker,

Apologies for the extended delay. multiple things have come up delaying my ability to look into the behavior you reported. I will hopefully be able to provide conclusions this week.

Regards,

Garrett

0 Garrett Kreger over 2 years ago in reply to Garrett Kreger

TI__Mastermind 27575 points

Hi Ryker,

I still do not see the behavior you report. Below waveform is what I consistently observe when removing vbus power testing on multiple EVMs.

Do you by chance have EN_OTG =1 in your test? Having OTG mode enabled would explain why PMID_GD initially goes low before going high again. If you are not enabling OTG please help to share all register settings you are setting in your test.

Best Regards,

Garrett

Power management

Power management forum

BQ25628EVM: The PMID_GD waveform of power-down has a sudden jump.