• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 441 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.

BQ2057W: BQ2057WSN broken

Matteo Colombo
Intellectual 300 points
Part Number: BQ2057W
Other Parts Discussed in Thread: BQ2057

Good morning everybody,

I'm using the BQ2057WSN in a project in order to recharge a 2S1P battery pack. The power supply that I use to recharge the battery as 12V output, with 4.5A max.

The design of the BQ2057 is implemented in order to have a recharge current of 500 mA, exactly the same circuit report in the documentation of the dedicated development board. The only difference is that I' using a MOSFET configuration in order to correctly manage heat and power dissipation.

The issue that I'm facing is that the BQ2057WSN gets damaged by continuously plug/unplug the power supply. What happen is that the charge current starts to increase and it goes up to 1.5A, until the chip get burned. After that I removed the chip from the PCB, replaced it with another one and start again to plug/unplug the power supply. Again the chip get damaged.

Everyone else ever faced this issue? Do you think it could be related to the layout of the PCB?

Best regards,

Matteo Colombo

  • 0
    TI__Guru* 75806 points

    Hello Matteo

    The most likely cause is a voltage transient that is exceeding the 18V max rating of the device.  

    Couple of things to take a look at:

    1.) How does the external power supply respond to a load step do you see any instability overshoot.

    2.) How long are the leads from external power supply to charger, the leads will act as an inductor and starting and stopping current flow will cause a voltage kick/overshoot.

    3.) Input filtering into charger, how large is it will adding more capacitance help reduce any possible overshoot.

    4.) Try measuring voltage at the BQ2057 VCC looking for overshoot during plug/unplug.

  • 0 in reply to Bill Johns
    Intellectual 300 points

    Hello Bill,

    it seems that that issue is solved by increasing the capacitate of the input filtering.

    Thank you very much for your hint.

    Best regards,

    Matteo Colombo