• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 356 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.

BQ27520-G4: SysDown Set Voltage Threshold

Ryan.Bishop
Expert 3900 points
Part Number: BQ27520-G4

Hello,

A customer is using bq27520-G4 in one of their products. We are wondering if there is a tolerance for SysDown Set Voltage Threshold. We weren't able to find this in the technical reference manual.  Can you comment on this please?

Thank you! Let me know if you have any questions.

Regards,
Ryan B.

  • 0
    TI__Guru* 76230 points
    Ryan
    This is based on their system. It is a voltage which they should set based on when they want the gauge reporting system down. You can use the default setting to act as a guidance . There isn't a threshold, it is system dependent. Eg the default setting has terminate voltage as 3200mV, the default" system down set voltage "is set to 3150mV

    thanks
    Onyx
  • 0 in reply to Onyx Ahiakwo
    TI__Expert 3900 points
    Hi Onyx,

    Thanks for your reply.
    I think the customer is interested in the tolerance of the SysDown threshold.

    So say they set SysDown to 3200mV, but could there be a 5% tolerance on that value? Meaning it could trigger anywhere between 3040mV and 3360mV.

    I obviously made up the 5% number, but can you tell me what that value really is?

    Thanks again,
    Ryan B.
  • 0 in reply to Ryan.Bishop
    TI__Guru* 76230 points
    There really isn't a tolerance. It just depends on how quickly the firmware responds to the voltage measurement. Note that cell voltage is measured every every 1s. So there will be some latency.
    thanks
    Onyx
  • 0 in reply to Onyx Ahiakwo
    TI__Expert 3900 points
    Hi Onyx,

    Okay understood. To put it in perspective, the customer will be setting SysDown Set to 3.25V and they want their battery voltage to never dip below 3V.

    They wanted to make sure any tolerance on SysDown Set wasn't so wide that 3.25V in reality could end up being closer to 3.1V. They want more margin than that.

    So ultimately, the only way the cell would go down to 3V is if it was being discharged so fast that it goes from >3.25V to 3V in one second?

    Thank you,
    Ryan B.