• 状态 TI Thinks Resolved
  • 回复 8 回复
  • 答案 1 答案
  • 订户 57 订户
  • 视图 216 视图
  • 用户 0 会员在此处
选项
选项
相关

BQ24780SEVM-583: BQ24780SEVM-583 ACDRV异常问题

ding zhu
Prodigy 10 points
Part Number: BQ24780SEVM-583
Other Parts Discussed in Thread: BQ24780S

Hi i have some problem with BQ24780S EVM Board, the VSYS output is abnormal, i have checked the BOM of the PCB Board, the VSYS droped after few pulse,the waveform shown as belows but i can normally accessed to the BQ Studio and can write&read register,i think it's weird,i also replaced 24780S and All Q1-Q5 MOS，still the same phenomenon，i cheked that the ACDET is 2.6V, ACOK 3.3V , REGN is 6V and Ilim>0.5mV, it's seemed that the ACDRV turn on is abnormal，could you give me some advice about that，does the board trigged the protection or the other schemetic components that i need to rechecked it, many thanks to your kindness help!

 

Red signal is Vsys blue is ACDRV and Green is CMSRC

_001.png_000.png

 

  • 0
    TI__Mastermind 39290 points

    Can you provide your schematic?

  • 0 回复 Vivian Gao
    Prodigy 10 points

    Hi, i‘m use the  BQ24780S EVM user’s guide schematic, the schematic is as belows，thanks for your reply

  • 0 回复 ding zhu
    TI__Mastermind 39290 points

    Can you provide a register dump?

    Do you have a system load? Do you see this issues without a system load?

    What is the battery voltage and charge current?

    Do you have a current limit on the input supply?

  • 0 回复 Vivian Gao
    Prodigy 10 points

    1. This is my register setting,copy from the Txt

    * Created: Wed Oct 22 14:44:13 CST 2025
    *
    * Format: Register Name tab Character,\t Hexadecimal register value.
    * Device: bq24780S
    * BQZ Container: Charger_1_00-bq24780S.bqz
    *
    Charge Option 0 8108
    Charge Option 1 C210
    Charge Option 2 0304
    Charge Option 3 1A46
    Prochot Option 0 4A54
    Prochot Option 1 8100
    Prochot Status 0000
    Charge Current 1FC0
    Charge Voltage 2EE0
    Discharge Current 7C00
    Input Current 1F80
    ManufacturerID 0040
    DeviceID 0030

    2. Yes,i have a system load, this issue will occur whether the load is connected or not, at the first time，i only connect the load at Vbatt, my mainly purpose is to test the Switching MOS, so i setting the register to charge the Vbatt, i connect it to the load and on the CV mode, when successfully write the register i found that the Vbatt do not have the output，finally i found that the Vsys is abnormal, the waveform is almost no difference in two circumstance.

     3.i do not use real battery， i only use load， Vbatt do not have output

    4. yes i have set current limit on both 2 source，3.3V is 1A and 19V is 5A，i also set lower Ilimit to see it,still the same issue

    5.I have try to remove the Battery monitor IC(in the circuit is U2) and disconnet JP6， still the same phenomenon.

  • 0 回复 ding zhu
    TI__Mastermind 39290 points

    Are you testing on an EVM or is your board similar to EVM?

    Is Adapter voltage falling below ACDET threshold?

    Can you exaplain your exact test setup?

  • 0 回复 Vivian Gao
    Prodigy 10 points

    The Test Board is produce by the gerber file form the Ti forum.

    Adapter voltage don't falling below ACDET threshold, i use source to provide 19V, i haven‘t seen the drop on the source, i’ll recheck it again.

    My exact test setup is first connect the Vin/3.3V/SMBUS and 2 load one load is on CC mode another is CV for BATT, turn on 3.3V and 19V input and then read&write register.

  • 0 回复 ding zhu
    TI__Mastermind 39290 points

    Can you provide scope capture of VIN and ACOK when this behvaior occurs?

    The ACFETs will shutoff, if ACOK goes low.

    These are the condition to prevent ACOK from going low.

    Can you confirm that ACOK does not go low and all these conditions are met?