BQ76952: Pin34 of the BQ76952 chip as VDD50.When initializing the BQ76952, VDD50 drop to 0V for about tens of milliseconds

Hello Zehu,

Do you mind sharing a schematic? This issue should not be related to any OTP or software, but I will double check and get back to you. A schematic might help for debugging in the meantime.

Regards,

Rohin Nair

Hi,Rohin

Thanks for your reply,

We are unable to provide the complete schematic . Which pin-related parts of the BQ76952 schematic do you need?

Best Regards,

zehu

Hello Zehu,

Is this issue only occuring during initialization or is it occuring after the device has fully initialized as well? Is REG2 configured to be automatically enabled? Make sure bit 4 in SETTINGS:CONFIGURATION: REG12 Config is set to 1. If this is not enabled, then REG2 will default to being disabled when initializing after reset or deepsleep.

Could you share the schematic related to pins 33-37?

Regards,
Rohin Nair

Hi,Rohin

It occurred during the initialization process. I'm confirming other information

Best Regards,

zehu

Hello Zehu,

Interesting. Thank you for the update. Please keep me informed as soon as you receive the remaining information.

Regards,

Rohin Nair

Hi Rohin,

Thanks for your continued follow-up. We’ve checked the code and confirmed that bit 4 in SETTINGS:CONFIGURATION: REG12 Config is indeed set to 1, so REG2 is enabled as required.

Additionally, we’ve prepared the schematic related to pins 33-37 of the BQ76952 as you requested.As shown as below.

Hopefully these information will help identify potential causes, and we’d appreciate your further insights on this issue.

Looking forward to your reply.

Best regards,

zehu

Hello Zehu,

Please give me some time to look over this. I will get back to you shortly.

Regards,

Rohin Nair

Hi Rohin,

Hope you're doing well. We haven't heard from you since you mentioned needing time to review the schematic and related information 17 days ago.

Could you please update us on the latest status of your review? Your feedback would be greatly appreciated to help us move forward with resolving this issue.

Looking forward to your reply soon.

Best regards,

Zehu

Hello Zehu,

I apologize for the delay.

What is the purpose of the R2022 resistor and C1329 cap?

Also, we recommend adding the REG2 cap to ground here as well. Besides these few things the schematic looks fine on this portion of your system. I will be going into lab today to see if we observe this VDD drop during initialization on our EVMs.

Regards,

Rohin Nair

1. Is this  reset mandatory during the initialization of the BQ76952?
2. Can we replace the reset with a partial reset (by pulling up the RESET_SHUT pin)?
3. Are there any risks associated with using a partial reset instead of a reset during initialization?

Best regards,

Zehu