• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 64 subscribers
  • Views 1753 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.

BQ24079 - Not charging the battery

Atul Bhakay
Genius 3205 points
Other Parts Discussed in Thread: BQ24079, BQ24075, BQ24075T

Hi,

       In our design we are using BQ24079 battery charger IC for charging 3.7V Li-Ion battery using USB.  The battery is not charging.  I have used the same schematic as that is shown in page 1 of the datasheet of BQ24079. Even the resistor values on ILIM and ISET are the same as per this schematic.

As per the table shown on page 6 - EN1 is high and EN2 is low, so i should get 500mA charging current. But I am not getting more than 10mA !!

Kindly advise what are the critical parameters that could lead to this problem

Regards

Atul Bhakay 

  • 0
    TI__Expert 7730 points

    What is the TS pin connected to? It should be connected to either a 10K NTC in the battery pack or a 10k ohm resistor to ground. Can you send me your schematic just to double check?

    Thanks,

    Wenjia

  • 0 in reply to Wenjia Liu
    Prodigy 40 points

    Atul and Wenjia,

    We are experiencing the same issue (with the BQ24075). I don't want to hijack your post, but we may be experiencing the same cause/effect.


    Our charge current for a 4.2V Li-ion is 1mA, and the TS pin's voltage is below (at 1mV) the thermal cutoff point defined in the datasheet. We have tried both a 10k NTC and a 10k resistor to ground on this pin with the same result (on two different PCBs).

    We also have the reference board HPA282 with the BQ24075 on it, and have configured it to match our schematic as much as possible. This circuit works fine.


    Schematic:

    Regards,

    Matt Dailey

  • 0 in reply to Matthew Dailey
    Prodigy 40 points
    Okay, I think I resolved our issue. We designed for the BQ24075, but purchased the BQ24075T. The part we're using requires external sourcing of the TS current, so not doing so will leave the voltage at 0. You may be experiencing the same issue, Atul. See the forum post below:

    e2e.ti.com/.../366772
  • 0 in reply to Matthew Dailey
    TI__Expert 7730 points

    Matthew, great and thanks for the referral.

    Atul, please let me know if you resolved the issue in the same way.

    Thanks,

    Wenjia