Because of the holidays, TI E2E™ design support forum responses will be delayed from Dec. 25 through Jan. 2. Thank you for your patience.

  • State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 3 answers
  • Subscribers 64 subscribers
  • Views 368 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

BQ25606: BQ25606: BQ25606 STAT pin stays low after battery charged

Fahad Ansari20
Intellectual 480 points
Part Number: BQ25606

Hi,

For my BQ25606 design, the STAT pin remains low even when the battery is completely charged.

I checked the current on battery. Our system takes 60mA current. When there is no charger at max battery level, the current out from the battery is 60mA, when I connect the charger, this current goes down to 45/47mA. 
From this, I feel that the charger is providing remaining 13/15mA of current and hence the STAT pin remains low, I have added a 10K resistor between VBUS and GND but same result

When I switch OFF the module with the charger still connected, the battery current goes to zero and the stat pin goes High, now when the module is turned ON, the STAT pin remains high. If I take out the charger and reinsert the charger, the STAT pin goes low again and stays low unless the module is turned off.

  • 0
    TI__Mastermind 25800 points
    Hey Fahad,

    Have you checked whether you are in a DPM state? Please verify whether, if during the CC charge phase, the charger is in VINDPM, IINDPM (through the ILIM pin or the D+/D- detection result), or whether the TS_WARM or TS_COOL conditions have been triggered.


    Regards,
    Joel H
  • 0 in reply to Joel Hernandez II
    Intellectual 480 points

    Hi Joel,

    I read through the datasheet but could not understand how can I check if my module is in DPM.

    Please help me in detecting it. What and how should I check on ILIM pin and where can I see/find D+/D- detection outcome?

    I am not using any tool currently and just have the hardware and that too on my board and not eval kit.

    Please let me know what next to try and thanks in advance for being so patient with me.

  • 0 in reply to Fahad Ansari20
    TI__Mastermind 25800 points
    Hey Fahad,

    If the charger is in VINDPM, the voltage as measured on the VBUS pin will the higher of 4.3V or VBAT+300mV. Check to see if this is the voltage on the charger.

    If the charger is IINDPM, the input current will be at a fixed value even if you increase the load. You can check this by applying an extra load on VSYS and see if the input current changes significantly.

    For either of these conditions, you can also check the battery current when your are in CC mode. If you are programming 1A of current for example, but see less than this when the charger is in CC mode (VBAT << VBATREG as measured at the pin), you are in some current limit.

    The outcome of the D+/D- detection will have to be determined by your answer to the IINDPM comment before. There are standard input current limits you will find on the charger as listed on Table 2. Input Current Limit Setting from D+/D– Detection. If the detection yield the unknown adapter, you will need to determine your setting on the ILIM pin based on the resistor you placed there.

    Lastly, please check the voltage on the TS pin with respect to the voltage on the REGN pin. If you divide these two, you will get that TS is a percentage of the REGN voltage. Compare this percentage to the parameters in the EC table. In between VT1 and VT2 or in between VT3 and VT5 means the charger is in either TS_COOL or TS_WARM, respectively, and termination is disabled.


    Regards,
    Joel H
  • 0 in reply to Joel Hernandez II
    Intellectual 480 points

    Hey Joel,

    Sorry for delayed reply

    VINDPM : VBUS = 5.1V, VBAT=4.08V

    IINDPM : IIN min load = 0.75A, IIN Full load = 0.82A (R ILIM is 240E)

    VTS-VREGN : not charging = 0.01V, charging = started at 1.89V and got stable at almost 2.155V (in less than a minute from charger connect time) VREGN = 4.18V so it is around 51% 

    From the above, what I understand is the device is not in VINDPM, not in IINDPM, D+/D- detection outcome suggests Divider 3 (1A current). Please suggest if my assumptions are correct and guide on what next to do

  • 0 in reply to Fahad Ansari20
    TI__Mastermind 25800 points
    Hey Fahad,

    When you say IIN min load = 0.75A, full load = 0.82A, is this the input current when you apply a load at SYS?

    From your measurement of the TS pin, it looks like the REGN voltage is very low. It should be fairly close to 5V based on your input at VBUS. I am not sure why it is at 4.18V. Can you also measure the PMID pin? It should be the same or similar to the VBUS voltage?

    One other thing to try if the TS pin is causing the issue is to directly force a voltage at the TS pin at about 55% of your measured REGN voltage (at the pin of the charger).


    Regards,
    Joel H