BQ76952: Query regarding OTP in the BMS IC

Phanidhar M

Part Number: BQ76952
Other Parts Discussed in Thread: BQSTUDIO, EV2400

This is a basic question. Once I program OTP in BQ76952, how should I ensure that it is correct? Secondly, can I program OTP multiple times? If so, how many times maximum can I do it? I have gone through the documentation but I am a bit unclear about this.

Thank you

over 1 year ago

0 Max Verboncoeur over 1 year ago

TI__Mastermind 25980 points

Hi Phanidhar,

I recommend looking at this FAQ, which should answer all your questions: (+) [FAQ] BQ76952: Common questions for OTP programming with the Bq769x2 Device Family - Power management forum - Power management - TI E2E support forums.

To validate your OTP write, you can power cycle or reset the device by entering and exiting SHUTDOWN mode and read the register values to see if they default to the new values.

Regards,

Max Verboncoeur

0 Phanidhar M over 1 year ago in reply to Max Verboncoeur

Prodigy 60 points

Thanks for your answer Maxwell. I am using BQStudio. So,I understand that inorder to enter and exit shutdown mode,the AFE should be connected to BQStudio using EVM2300 with 12V and the SHUTDOWN command should be sent twice, once for entering shutdown and the second time for exiting shutdown. Then the register values should have the new values. Request you to correct me if I am wrong with my understanding.

Thank you

+1 Max Verboncoeur over 1 year ago in reply to Phanidhar M

TI__Mastermind 25980 points

Hi Phanidhar,

The SHUTDOWN command should be sent twice in quick succession to command the device to enter SHUTDOWN mode. To exit SHUTDOWN mode the TS2 pin should be pulled low and then released. When the device exits SHUTDOWN mode, it will load the default/OTP settings into the RAM. This is explained in more detail in Section 7.5 of the TRM.

I recommend using an EV2400. The EV2300 hasn't been tested with the bq76952 and may not be fully compatible.

Regards,

Max Verboncoeur

0 Phanidhar M over 1 year ago in reply to Max Verboncoeur

Prodigy 60 points

Thanks for the reply Maxwell. Okay so now I understand why sometimes EV2300 will not communicate properly with BQ Studio. Sometimes its like it loses connection within 30-40s frequently.

0 Max Verboncoeur over 1 year ago in reply to Phanidhar M

TI__Mastermind 25980 points

Hi Phanidhar,

The EV2400 received several firmware updates to ensure compatibility with the bq76952; the EV2300 did not receive these updates.

Regards,

Max Verboncoeur