BQ40Z50: PEC Disable

Zeming Kong

Part Number: BQ40Z50
Other Parts Discussed in Thread: BQ24770, BQSTUDIO, EV2400

Hi team,

My customer is evaluating our charger IC BQ24770 used to charge a smart battery embedded with BQ40z50, and he needs PEC(Packet Error Code) communication function.

I have inquired charger team if our charger IC can support PEC, and I was told that we don't have such products, PEC should be disabled if BQ24770 is used because it cannot support PEC.

And when we tried to use bqstudio to disable PEC by configurating the CPE bit, it was sealed and the value is 00(disabled, default), so we want to confirm that if BQ40z50 is compatible with BQ24770 without configuration, and how can we enable PEC because this function is necessary?

Please see another thread for more information.

https://e2e.ti.com/support/power-management/f/power-management-forum/981081/bq24770-smart-battery

Best,

Zeming

over 4 years ago

0 Nick Brylski over 4 years ago

TI__Mastermind 19195 points

Hi Zeming,

Did you try unsealing the device first before setting CPE?

Best regards,

Nick

0 Zeming Kong over 4 years ago in reply to Nick Brylski

TI__Expert 3515 points

Hi Nick,

Yes, we tried but security key is needed, we entered the default key but nothing changed, so we were wondering if the security key was not correct.

Best,

Zeming

+1 Nick Brylski over 4 years ago in reply to Zeming Kong

TI__Mastermind 19195 points

Hi Zeming,

To go from SEALED to UNSEALED, these two words must be sent to ManufacturerAccess() (MAC), first 0x0414 followed by 0x3672, both sent sequentially with the second word sent within 4 seconds of the first.

In addition, try the UNSEAL button in the bqSutdio and implement the same sequence in your host.

I would suggest you try unsealing the bq40z50 device using bqStudio and EV2400.

0 Zeming Kong over 4 years ago in reply to Nick Brylski

TI__Expert 3515 points

Hi Nick,

Thanks for your reply. But this didn't work.

We were wondering if the battery manufacturer had set a new security key. Maybe we need to confirm this with the battery manufacturer.

Thanks a lot for your support !

Best,

Zeming

0 Zeming Kong over 4 years ago in reply to Zeming Kong

TI__Expert 3515 points

Hi Nick,

Sorry for open this thread again.

We tried the default key again to unseal CPE, and SBS configurations all turned to 00 from SEALED, then we tried to change the CPE value to 01, but still 00. Do you know why we cannot write the value? Have we unsealed it successfully?

Best,

Zeming

+1 Jessica H. over 4 years ago in reply to Zeming Kong

TI__Genius 11535 points

Hi Zeming,

Is your device in Full Access mode? To check if it is sealed, unsealed, or in full access you can look at the SEC1, SEC0 bits under the Operation Status A register.

0 Zeming Kong over 4 years ago in reply to Jessica H.

TI__Expert 3515 points

Thanks. We have confirmed.

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BQ40Z50: PEC Disable