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WEBENCH® Tools/BQ35100: Battery Alert's BATLOW bit doesn't clear

Part Number: BQ35100
Other Parts Discussed in Thread: BQSTUDIO

Tool/software: WEBENCH® Design Tools

Hello

I'm using a bq35100EVM and BQStudio and I'm trying to understand the behaviour of /ALERT pin.

I have plugged the BAT+ and BAT- of my gauge on a regulated DC power supply. When I set the voltage under the low battery threshold, /ALERT output is triggered, ALERT bit from BatteryStatus register is set, and BATLOW bit from BatteryAlert register is set.

When I read all register, /ALERT output  and ALERT bit come back to normal. BATLOW bit from Battery Alert register is still equal to 1.

Then I increase my voltage until it exceeds "Batlow Voltage Clear Threshold", but BATLOW bit does not clear.

According to Technical Reference : "An ALERT bit only clears if the condition for it is removed."

So is this a normal behaviour ?

Thanks by advance.

Arthur

  • Hello Arthur,
    We will respond to this shortly
    thanks
    Onyx
  • Arthur,

    I have just finished verifying the functionality. Here is a breakdown for key points of how the alerts will work. 

    1) Gauge must be in an active state (GA=1) or condition is true at startup

    2) Once BATLOW < threhsold for delay time Batlow flag will come on. If BATLOW Alert config = 1 the alert pin will activate and alert flag = 1

    3) Alert pin will remain active until the alert register is read (0x0b). Triggering another Alert will not pulse it, it will just remain active.

    4) BATLOW is intended to be sticky. There is no clear for the flag until GE is driven low and power is removed from the IC. If you have a config file where is shows a battery recovery parameter please let me know which bqstudio you are using so i can trace it back to its source. 

    4) Temp conditions will recover, but alert pin will not be cleared until register is read. 

    Let me know if you have any other outstanding questions

    Thanks,

    Eric Vos


    Thanks,
    Eric Vos