BQ27427: Sleep mode

Hello Ishiwata.

1.1) Yes, for the BQ27427 please refer to the Technical Reference manual attached below
-section of SLEEP mode in page 10 and also reference it throughout the document.
https://www.ti.com/lit/ug/sluucd5/sluucd5.pdf?ts=1739300470600&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ27427
-Read through the "Technical Document" section to find more information 

1.2.) Below I attached the documentation of the sleep mode on the BQ27426
-section of SLEEP mode in page 13 and also reference it throughout the document.
https://www.ti.com/lit/ds/symlink/bq27426.pdf?ts=1739301041142&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ27426
-Ultra low power system documentation 
https://www.ti.com/lit/ta/sszta71/sszta71.pdf?ts=1739301258563&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ27426
-Read through the "Technical Document" section to find more information 
-https://www.ti.com/product/BQ27426

2.)The chip uses Impedance Tracking technology and within the BQStudio software the user is able to get all the values form Total run time, Cycle Count, SOH degradation state, SOC remaining, Cell voltage. In terms of Current values, both previously mentioned chip have a external sense resistor to monitor the current values of the load

Technical document of Impedance tracking
-https://www.ti.com/lit/an/slua450a/slua450a.pdf?ts=1739302128115&ref_url=https%253A%252F%252Fwww.ti.com%252Fsitesearch%252Fen-us%252Fdocs%252Funiversalsearch.tsp%253FlangPref%253Den-US%2526nr%253D10318%2526searchTerm%253Dimpedance+tracking
-https://www.ti.com/video/6287050244001

BQ27427 

-EVM explains the setting to use with BQStudio 
https://www.ti.com/lit/ug/sluucd7/sluucd7.pdf?ts=1739301937537&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ27427

BQ27426
-EVM explains the setting to use with BQStudio
https://www.ti.com/lit/ug/sluube1/sluube1.pdf?ts=1739302245680&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ27426

Hello Alan,

Sorry for the late response.
Your support is appreciated.
I have an additional question.

I checked the Technical Reference for BQ27426 and the Technical Reference for BQ27427, but I was unable to find any registers for the following parameters.

- I could not find any registers for the usage time (cumulative operating time) and number of cycles for BQ27426 and BQ27427.
- I also could not find a register for SOH for BQ27427.

Is it possible to obtain registers for the above?
If so, please tell me what the register is.

Best Regards,
Ishiwata

Hello Ishiwata,

After doing more research, the technical reference manual is missing the state of health but you can locate it in the BQStudio register tab, the address is 0x20. Also this gauge does not report the usage time aswell/

Thank you,
Alan

Hello Alan,

Please let me know just to confirm.

The BQ27427 cannot obtain SOH. The BQ27426 can obtain SOH.

Is my understanding of the above correct?

However, the BQ27427 EVM document shows SOH in Figure 7-1. Registers Screen. Is this a typo?

Again, I would like to ask: are there registers for the usage time (accumulated operating time) and number of cycles for the BQ27426 and BQ27427?

Best Regards,
Ishiwata

Hello Ishitwata, 

Both BQ27426 and BQ27427 both have SOH but on BQ27427 (address is 0x20) it is not listed on the Technical reference manual also figure 7-1 is not a typo however it is a read only feature. There is no accumulated time feature for both BQ27426 and BQ27427 IC's.

Thank you,
Alan

Hello Alan,

Thanks for your reply.

I understand that there is no cycle count register for both the BQ27426 and BQ27427, is that correct?

Best Regards,
Ishiwata

Hi All,

I have been waiting for your reply, but have not heard from you.
Could you give us a response?

Best Regards,
Ishiwata

Hello Shuji,

There is no cycle counter for  both the BQ27426 and BQ27427.

Thank you,
Alan

Hello Alan,

Thank you for your answer.

You commented that the BQ27427's SOH can be read at address 0x20, but do you have any documentation to show that?

Best Regards,
Ishiwata

Hello Jonny,

Thanks for your reply.

Are there any other detailed documents about the artwork for BQ27426 or BQ27427 besides the datasheet?

Best Regards,
Ishiwata

Hello Shuji,

Yes all the documentation for both the BQ27426 and the BQ27427 can be founded under the Technical documents, I would mainly look at the datasheet, technical reference document and the EVM documents along with the supplementary documentation as well.

Product page:

BQ27426:https://www.ti.com/product/BQ27426

BQ27427: https://www.ti.com/product/BQ27427

Thank you,
Alan