• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 269 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ25730: VIN_DPM, IIN_DPM, Charge Current

Ali hammoud
Prodigy 70 points
Part Number: BQ25730
Other Parts Discussed in Thread: BQSTUDIO, , BQ25723

Tool/software:

Hello,

I am encountering an issue with the VIN_DPM, IIN_DPM, and charge current settings on the BQ25730 in my design. Here is the setup:

I am designing a charge control board for a 4S 18650 battery pack, using USB-PD as the power input source (20V, 3A). My design closely follows the EVM schematic, with one notable difference: I am not using CMPIN or CMPOUT. In my implementation, CMPIN is tied to GND, and CMPOUT is left floating.
The BQStudio register settings I am using are as follows:

Charge Option 0    E70E
Charge Current    0200
Max Charge Voltage    41A0
OTG Voltage    09C4
OTG Current    3C00
Input Voltage    2380
Min System Voltage    7B00
IIN_HOST    1F00
Charger Status    8400
Prochot Status  B800
IIN_DPM    1F00
ADC VBUS and PSYS    CB00
ADC IBAT 0800
ADC IIN and CMPIN    0800
ADC VSYS and VBAT    CDC6
Manufacture ID    D540
Device ID    00D5
Charge Option 1    3200
Charge Option 2    0037
Charge Option 3    0429
Prochot Option 0    4A81
Prochot Option 1    41A0
ADC Option    A0FF
Charge Option 4     0048
Vmin Active Protection    006D

Currently, I am measuring VSYS at 15.6V. However, I am facing the following issues:

  1. The charge current drops to 0A after a few minutes of charging.
  2. The ADC IIN reading is significantly lower than expected, approximately 1100mA instead of 3A.

Could you help me identify what might be causing these problems? Are there any adjustments needed in my configuration to resolve this?

Thank you for your assistance!

Best regards,

Ali

  • 0
    TI__Mastermind 32715 points

    It looks a thermal problem. Suggest ordering a BQ25730EVM and try it.

  • 0 in reply to Tiger Zhou
    Prodigy 70 points

    Hallo Tiger,

    Thank you for your response. I will try to order the EVM and test it.

    After disabling the watchdog timer, the charge current no longer drops to 0A. However, I am still unable to get proper readings for the input current in forward mode or for the discharge current in battery-only mode, even when setting En_IBAT and EN_OTG to high in battery only mode.

    Is there anything else I should be setting to obtain the discharge current reading?

    Regards,

    Ali

  • 0 in reply to Ali hammoud
    TI__Mastermind 31376 points

    Hello Ali,

    What values are you using for the input and charging sense resistors?

    As Tiger mentioned, it will be best to test on EVM, to see if this is an issue with your board design.

    Best Regards,

    Christian

  • 0 in reply to Christian Moyer
    Prodigy 70 points

    Hello Christian,

    Thank you for your response.

    For the input, I am using 11V to ensure it does not drop below this level. Additionally, I am using 10 mΩ sense resistors.

    However, my current issue is that when there is no power input and I am only using the battery, I am not getting any reading for the discharge current.

    I would appreciate your insights on this matter.

    Kind regards,
    Ali


  • 0 in reply to Christian Moyer
    Prodigy 70 points

    As an update, I do have the EVM for the BQ25723. I am running the same scenario with a 4S cell configuration, but I am still not getting any reading for the discharge current, even when using a digital load and observing a discharge of 1A at 15V.

    Thank you for your assistance!

    Charge Option 0	E70E
Charge Current	0000
Max Charge Voltage	41A0
OTG Voltage	09C4
OTG Current	3C00
Input Voltage	0000
Min System Voltage	7B00
IIN_HOST	4100
Charger Status	0000
Prochot Status	B800
IIN_DPM	4100
ADC VBUS and PSYS	0000
ADC IBAT	0000
ADC IIN and CMPIN	0000
ADC VSYS and VBAT	0000
Manufacture ID	E040
Device ID	00E0
Charge Option 1	B300
Charge Option 2	00F7
Charge Option 3	9434
Prochot Option 0	4A09
Prochot Option 1	41A0
ADC Option	E0FF
Charge Option 4	0048
Vmin Active Protection	0004

  • +1 in reply to Ali hammoud
    TI__Mastermind 31376 points

    Hello Ali,

    Ali hammoud said:
    However, my current issue is that when there is no power input and I am only using the battery, I am not getting any reading for the discharge current.

    When there is no input, the device is automatically in lower power mod.

    Please refer to the EN_LWPWR bit in the datasheet. ADC is not available in low power mode. Disable low power mode.

    This should resolve the issue.

    Best Regards,

    Christian.