BQ27Z746: [Re] BQ27Z746 Programming issue

YUXUAN CHIANG

Part Number: BQ27Z746
Other Parts Discussed in Thread: BQSTUDIO

Hi TI Teams,

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1590291/bq27z746-bq27z746-programming-issue

This is a follow-up question related to the issue in the previous link.
However, I’m currently unable to communicate with the IC using address 0x16 — the IC always responds with NACK.
Could you advise me on how to resolve this issue?

Thanks.

Steve.

5 months ago

0 Alan Frias 5 months ago

TI__Mastermind 39525 points

Hello,

This question has been assigned and will be reviewed by someone on the team when possible. In the meantime please attach .gg/.log/ data files associated with the project.

Thank you,
Alan

0 Jonny 5 months ago in reply to Alan Frias

TI__Mastermind 27471 points

Hello,

The device should ACK at either the I2C address or the ROM address depending on what mode the gauge is in. Please ensure that the I2C lines are pulled up to a steady 3.3V source. It might be helpful if you send over a logic analyzer capture of the comms. If everything looks good with comms then it is possible that the device was damaged.

Regards,

Jonny.

0 YUXUAN CHIANG 5 months ago in reply to Jonny

Prodigy 225 points

Hi Jonny,

https://drive.google.com/file/d/1ZvT1H-RNVDdq-3ftd35tPPUIT8y1ZDxu/view?usp=sharing

The waveform file can be opened using the software available at the download link below.

https://saleae.com/downloads

Thanks.

Steve.

0 Jonny 5 months ago in reply to YUXUAN CHIANG

TI__Mastermind 27471 points

Hello,

Can you please directly link the files to E2E. I am unable to open the google drive.

Regards,

Jonny.

0 YUXUAN CHIANG 5 months ago in reply to Jonny

Prodigy 225 points

Hi Jonny,

Sorry, the attachment contains the related files.
Please help me check them again. Thank you!

Session 7.zip

Steve.

0 YUXUAN CHIANG 4 months ago in reply to YUXUAN CHIANG

Prodigy 225 points

Hi Jonny,

May I ask if there are any results from the analysis?
Thank you!

Steve.

0 Jonny 4 months ago in reply to YUXUAN CHIANG

TI__Mastermind 27471 points

Hello,

It appears there is something fundamentally incorrect with your communication structure. The I2C lines appear to be pulled down instead of being pulled up. This could be the cause of the issue.

Regards,

Jonny.

0 YUXUAN CHIANG 4 months ago in reply to Jonny

Prodigy 225 points

Hi Jonny,

The I2C lines are indeed pulled high, but the lines were being pulled low when there was no communication. I will modify this part.
Aside from that, are there any errors in the communication commands?

Thanks.

Steve

0 Jonny 4 months ago in reply to YUXUAN CHIANG

TI__Mastermind 27471 points

Hello Steve,

I would start with addressing the issue mentioned in my previous response then we can go from there.

Regards,

Jonny.

0 YUXUAN CHIANG 4 months ago in reply to Jonny

Prodigy 225 points

Hi Jonny,

I have corrected the issue where the I2C lines were pulled low during idle, but after the fix, the IC still continues to respond with NACK.

6013.BQ27Z746.zip

Thanks.

Steve

0 YUXUAN CHIANG 3 months ago in reply to YUXUAN CHIANG

Prodigy 225 points

Hi Jonny,

Is there any update？

Thanks.

Steve.

0 Jonny 3 months ago in reply to YUXUAN CHIANG

TI__Mastermind 27471 points

Hello,

With the pullups added to the I2C lines, is there any ACKs at the I2C address (0xAA)? Are you able to communicate using bqStudio?

Regards,

Jonny.

0 YUXUAN CHIANG 3 months ago in reply to Jonny

Prodigy 225 points

Hi Jonny,

The same issue occurs when using bqStudio — there is still no ACK.

Thanks.

Steve.

0 Jonny 3 months ago in reply to YUXUAN CHIANG

TI__Mastermind 27471 points

Hello,

Are you seeing this behavior across multiple units, or is this isolated?

Regards,

Jonny.

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BQ27Z746: [Re] BQ27Z746 Programming issue