• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 63 subscribers
  • Views 1394 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.

BQ24232HA: CHG pin stays low even battery is fully charged

Theen Poh Loh74
Prodigy 30 points
Part Number: BQ24232HA
Other Parts Discussed in Thread: BQ24230, BQ24232, BQ24232H

Hi TI Community,

BQ24232HA is currently used to charge a single-cell li-ion pouch cell battery pack from a USB source .

Charging current is set at 0.48A and termination current is at 48mA.

5 boards have been built to charge the batteries and all of the boards are having the same symptom of CHG pin not able to go into high impedance mode even though termination current is reached.

Could you please help and advice what could be the reason.

Thank you in advance.

  • 0
    TI__Guru 67476 points

    The circuit looks OK, do not see any problem.

    Charge current should be 0.48A and termination should be 10% or 48mA.

    A couple of things to check:

    1.) Double check that you have a bq24232 installed on your boards and not the bq24230.  Pin 15 function changes on the 230 and can possibly disable charge complete.

    2.) Check the connection of thermal pad on the device it should be connected to Gnd (VSS)

    3.) Check the voltage at ISET, it is portioned to output current and will be used for termination at 48mA.  What are you seeing at about 48mA?

  • 0 in reply to Bill Johns
    Prodigy 30 points

    Hi Bill,

    Thanks for your reply.

    I've verified the following.

    1.) The charger that I'm currently using is BQ24232 as the following silkscreen "4232HA TI 64I AFSG" is indicated on the IC itself.

    2.) The connection of IC thermal pad is being connected to a PCB ground pad beneath the IC itself.

    3.) Voltage at ISET during charging (0.48A) is 2.08V; voltage at ISET when fully charged (48mA) is 28mV.

  • 0 in reply to Theen Poh Loh74
    TI__Guru 67476 points

    I set up a bq24232H EVM with your configuration and tested the termination function and /CHG output. 

    Did not see any problem, charge will complete right at 48mA and /CHG pin will transition from low impedance to high impedance.

    Also noted that the pin will remain high impedance during charge restarts, battery voltage drops and charge restarts.

    Any other details of your circuit that would help?

    Do you have a layout I can review?

  • 0 in reply to Bill Johns
    Prodigy 30 points

    Hi Bill,

    The battery charger circuit OUT pin is connected to a step-up dc-dc converter with 5V output and supplying 80mA of load.

    The battery charger circuit layout is as follows.

    Regards,

    Theen Poh