• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 314 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.

bq34z100evm mesuring current in noisy envirement

Fabian Grob
Prodigy 140 points
Other Parts Discussed in Thread: BQ34Z100EVM, BQEVSW

Hello


I

am trying to measure the current coming from a RC LiPo charger with the bq34z100evm board.

If I use a stabilized power supply and a Fluke amp-meter and adjust the current to 500mA showing on the amp-meter the bqEVSW software shows 500mA. If I use the RC LiPo charger adjust it to 500mA, the Fluke amp-meter shows 500mA but then the bq34z100evm board reads only about 400mA. If I use the same setting with the LiPo charger on a bq20z45evm board I see 500mA with the bqEVSW software.

Do you have any suggestions why the bq34z100evm reads a 25% smaller current with the RC LiPo charger than with the stabilized power supply.


Regards Fabian

  • 0
    TI__Guru 73830 points

    I have not seen that problem before. The device just measures the voltage drop across the sense resistor, so it should report 500mA. We have seen issues with the Board Offset calibration where is caused about a 6mA error. You can try setting the Board Offset parameter to 0 in data flash and recalibrate the full scale current to see if that helps.

  • 0 in reply to ThomasCosby
    Prodigy 140 points

    Hi Thomas

    Thanks for the quick answer. I solved the problem it was related to the LiPo charger. Some current was flowing through the LiPo charger earth ground – Computer – EV2300 –I2C – connector back to the bq34z100evm board.

     

    Regards Fabian