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BQ25672: BQ25672 charging issue

Manish Mistry
Prodigy 150 points
Part Number: BQ25672

Tool/software:

Hi,

I am using BQ25672RQMR for battery charging (2000mAh single cell). 
I tried to charging my battery but not able to charge the same.
Can you please let me know what is missing?? I am attaching here with the schematic.
4744.schematic.pdf
Regards,
Manish Mistry
  • 0
    TI__Guru**** 165766 points

    Hi Manish,

    I assume you want to jumper select either a solar supply or other power source.  If so, VACx must be connect directly to VBUS pins as shown below.

    Regards,

    Jeff

  • 0 in reply to Jeff F
    Prodigy 150 points

    Hi Jeff,

    Thanks for reply. Its already connected. We are getting PMID 5V but not able to get REGN voltage when VBUS external source is applied.

    Only battery option, we are able to get REGN voltage. No idea what is missing.

    Regards,

    Manish Mistry

  • 0 in reply to Manish Mistry
    TI__Guru**** 165766 points

    Hi Manish,

    With battery only, the charger only outputs REGN voltage =5V if the ADC TS channel is on continuous read.  PMID is input to REGN LDO. Is ILIM_HIZ accidentally shorted to GND, thereby forcing the charger in HiZ mode?

    Regards,

    Jeff

  • 0 in reply to Jeff F
    Prodigy 150 points

    Hi Jeff,

    ILIM_HIZ is connected to the voltage divider circuit.

    Still its not working. can you see missing.

  • 0 in reply to Manish Mistry
    TI__Guru**** 165766 points

    Hi Manish,

    I do not see any other issues.  Do you have a BQ25672EVM that you can configure and test?  In battery only, REGN output should be zero not 5V unless the ADC TS channel is enabled.

    Regards,

    Jeff

  • 0 in reply to Jeff F
    Prodigy 150 points

    Hi Jeff,

    thanks for the reply. we have tried using I2C code & its working but one issue found that using solar panel charging is going on but when we cover solar panel charging is not working after removing the cover. After uncover solar panel check more than 15min in sunlight but no succes. 

    When we shorted D+ & D- at that charging retry within 2min. 

    Can you guide me on this issue.

    Regards,

    Manish Mistry

  • +1 in reply to Manish Mistry
    TI__Guru**** 165766 points

    HI Manish,

    EN_MPP bit = 1, which auto remeasures input voltage and sets VINDPM to VINDPM% x open circuit voltage, resets to 0 if V(BAT) drops below MINSYS.  That means that VINDPM auto sets to the measured open circuit voltage minus either 0.7V for low voltages or 1.4V for high voltages.  VINDPM does not reset to lower value for a cloud passing over the panel that lowers the panel's open circuit voltage.  If the panel voltage drops below the fixed VINDPM threshold but not below VBUS_UVLO, the converter turns off and does not turn on again until the voltage increases.  So I recommend setting MINSYS as low as possible to keep MPP operating as long as possible.  

    If the battery discharges completely and cannot prevent V(SYS) from dropping below 2V SYS SHORT threshold, the converter auto sets EN_HIZ=1.  Because SYS is now 0V, the only way to exit HIZ state is for the input voltage to dip below VBUS_UVLO~=3.4V.

    Regards,

    Jeff