• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 292 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.

Original question:

BQ24092: BQ24092

BQ24092: BQ24092

DVI17
Prodigy 100 points
Part Number: BQ24092
Other Parts Discussed in Thread: BQ24040, BQ24090, BQ25100, BQ21040, BQ24050

Hi ,

I use BQ24092 on my charger to charge Li-ion battery. Usually the charge voltage of fully charged is almost 4.2V (above 4.19V)  However, one chip output of fully charged is sometimes 3.9V, sometimes is 4.19V. I don't know what cause the chip output shift. Anybody has an idea on this issue? Thanks in advance for any advice.

Bo

  • 0
    TI__Guru 65846 points

    Hi Bo

    I have a couple of things you can check:

    1.) The BQ24092 will reduce charge voltage from 4.2V to 4.1V at high battery temp (JETA standard). Not quite 3.9V but something that will reduce voltage.

    2.) Resistance between the battery and OUT pin will off set voltage sensed by the device, increase sensed voltage.  Check for resistance in this and return path.

    3.) Check the input voltage to rule this out as a possible problem.

    4.) PRETERM setting, typical value is 10% (open or 2k)  -- if this value is on the high side 50% it may be a factor.

    NOTE -- TS Pin voltage will reduce voltage to 4.1V -- 278mV to  178mV. The thermal shutdown hot is 178mV.

  • 0 in reply to Bill Johns
    Prodigy 100 points

    Hello Bill,

    I found your post of “Troubleshooting tip” on Power Management Forum in Jan 2019. It explains very clearly. My TS pin voltage is low when low output voltage occurs.  The issue is caused by the bad connection between the thermistor and the board.  Now the problem is solved. Thank you so much.  

     

    Best Regards,

    Bo

  • 0 in reply to DVI17
    TI__Guru 65846 points

    Hi Bo

    thanks for the update and feedback.

    The BQ2409X is similar to the BQ24040 and much of the troubleshooting / FAQ / Tip&Tricks apply.

    Some good links:

    •FAQ Generated – BQ2404X also applies to BQ21040, BQ24050, BQ24090 and BQ25100 family of devices.
    –/CHG pin behavior--BQ24040 and BQ2404X family Charge Complete Pin Behavior, /CHG
    e2e.ti.com/support/power-management/f/196/t/753020
    –Vin vs Vout dropout--BQ24040 and BQ2404X family Vin to Vout vs Charge Current Regulation.
    e2e.ti.com/support/power-management/f/196/t/760760
    –TS pin modes--BQ24040 and BQ2404X family TS pin configuration of NTC and TTDM mode
    e2e.ti.com/support/power-management/f/196/t/762756
    –Troubleshooting tips & tricks--BQ24040 and BQ2404X family Trouble Shooting Tips, No Output, Charge Current Low, Early Termination and Others.
    e2e.ti.com/support/power-management/f/196/t/763227
    BQ24040 -- Quick Start Guide -- SLUA901
    www.ti.com/lit/an/slua901/slua901.pdf