BQ25703A: ADC operation does not complete

Manabu Yabe

Part Number: BQ25703A
Other Parts Discussed in Thread: , BQ25713

Hi TI,

ADC operation does not complete under certain conditions.
I was able to reproduce this issue on the BQ25703AEVM-732 evaluation board as well.

How to reproduce
1. Execute "Battery Management Studio"
2. Select "Charger_1_00-bq25703A.bqz"
3. Select "Tgt Address : D6(6B)"
4. Select "Update mode : immediate"
5. supply power to "BQ25703AEVM-732" VBAT terminal (battery only operation)
6. Read Register (Read chip default value)
7. Charge Option 0 -> EN_LWPWR : Uncheck
8. Charge Option 1 -> CMP_DEG : Comparator Disable
9. Prochot Option 1 -> EN_PROCHOT_ICRIT : Uncheck
10. ADC Option -> EN_ADC_xxx(any port) : Check
11. ADC_Option -> ADC_START : Check
12. Click "Read Register", but AD conversion does not complete (ADC_START bit does not become 0)

I want to know the cause of the problem.
I am attaching the register file.

Sincerely,

Fullscreen BQ25703A_Registers.txt Download

* Created: Fri Nov 25 17:30:58 JST 2022
*
* Format: Register Name  tab Character,\t  Hexadecimal register value.
* Device: bq25703A
* BQZ Container: Charger_1_00-bq25703A.bqz
*
Charge Option 0	620E
Charge Current Register	0000
Charge Voltage Register	20D0
OTG Voltage Register	0000
OTG Current Register	0000
Input Voltage Register	0000
Minimum System Voltage	1800
Input Current Register	4100
Charge Status Register	2000
Prochot Status Register	0000
Input Current Limit In Use	4100
VBUS and PSYS Voltage Read Back	0000
Charge and Discharge Current Read Back	0000
Input Current and CMPIN Voltage Read Back	0000
System and Battery Voltage Read Back	0000
Manufacture ID and Device ID Read Back	7840
Device ID Read Back	0178
Charge Option 1	0201
Charge Option 2	02B7
Charge Option 3	0000
Prochot Option 0	4A54
Prochot Option 1	8100
ADC Option	6001

over 2 years ago

0 Khalid Bairuti over 2 years ago

TI__Expert 4780 points

Hello Manabu,

Thank you for the detailed step by step. Can you try the following things and let me know if you still see the issue in these scenarios?

- Power up with Adapter (Assume above is with Battery only as AC_STAT = 0 in register dump) -> Does issue still occur?
- With Battery only, Set ADCOption in two steps -> Step 1: Set ADCOption to 0x2001 to enable ADC VBAT, Step 2: Set ADCOption to 0x6001 to enable ADC_START

Thanks,
Khalid

0 Manabu Yabe over 2 years ago in reply to Khalid Bairuti

Prodigy 20 points

Hi Khalid,

>- Power up with Adapter (Assume above is with Battery only as AC_STAT = 0 in register dump) -> Does issue still occur?
the ADC_START become 0.

>- With Battery only, Set ADCOption in two steps -> Step 1: Set ADCOption to 0x2001 to enable ADC VBAT, Step 2: Set ADCOption to 0x6001 to enable
the ADC_START become 0.

Can you reproduce it on your board ?

Sincerely,

0 Khalid Bairuti over 2 years ago in reply to Manabu Yabe

TI__Expert 4780 points

Hello Manabu,

I will check this by tomorrow.

Khalid

+1 Khalid Bairuti over 2 years ago in reply to Khalid Bairuti

TI__Expert 4780 points

Hello Manabu,

I can see the same behavior on my board.

How to reproduce
1. Execute "Battery Management Studio"
2. Select "Charger_1_00-bq25703A.bqz"
3. Select "Tgt Address : D6(6B)"
4. Select "Update mode : immediate"
5. supply power to "BQ25703AEVM-732" VBAT terminal (battery only operation)
6. Read Register (Read chip default value)
7. Charge Option 0 -> EN_LWPWR : Uncheck
8. Charge Option 1 -> CMP_DEG : Comparator Disable
9. Prochot Option 1 -> EN_PROCHOT_ICRIT : Uncheck
10. ADC Option -> EN_ADC_xxx(any port) : Check
11. ADC_Option -> ADC_START : Check
12. Click "Read Register", but AD conversion does not complete (ADC_START bit does not become 0)

I found that Step 9 can impact the result. Can you try with skipping Step 9?

Khalid

0 Manabu Yabe over 2 years ago in reply to Khalid Bairuti

Prodigy 20 points

Hi Khalid,

In our investigation as well, we found that the ADC works normally if step 8 or step 9 is skipped.

Can you explain the mechanism and the reason why this issue occurs?
Does skipping step 9 guarantee that the ADC will never hang?

Sincerely,

0 Khalid Bairuti over 2 years ago in reply to Manabu Yabe

TI__Expert 4780 points

Hello Manabu,

Once your process works it is repeatable and you should not see issues with the ADC hanging. If you don't prefer this procedure you could also try our newer family BQ25713 which should not have the same issue.

Khalid

0 Manabu Yabe over 2 years ago in reply to Khalid Bairuti

Prodigy 20 points

Hi Khalid,

I got it.
Leave EN_PROCHOT_ICRIT or CMP_DEG enabled.

Thank you.

Sincerely,

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BQ25703A: ADC operation does not complete