• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 64 subscribers
  • Views 888 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.

bq34z100 Alert pin problem

Rob D
Prodigy 40 points
Other Parts Discussed in Thread: BQ34Z100, BQEVSW

I am working with the bq34z100 demo board and I believe I have discovered a problem with using the alert pin.

The trouble is that the alert pin will only go low for some of the alert flags but not others.

If I set [Cell BH set threshold] to just above my idle battery voltage and then flip on the charger to make it exceed the threshold I see the flag become set in bqEVSW and at the same time I see the alert pin pulled low.  However, if I set [Chg Inhibit Temp High] to 35C and warm the thermistor to exceed 35C I do see the [Chg_INH] flag become set in bqEVSW but the alert pin never goes low in this case.  I had the [Alert Configuration] register set to 0x2800 during these two tests.

I have tested several of the alert flags and have found that [CHG_INH, FC, and DSG] all become set when they should in the [Flags] register but even with the appropriate bits set in the [Alert Configuration] register I have never seen the alert pin go low for these flags. I have also tested the [BATHI and SOC1] flags and have found that they both pull the alert pin low as expected when they become set in the [Flags] register.

Other usefull info is that I have the [LED_Comm Configuration] register set to 0x00 and I have wired to the alert pin P2 (Pin1).  I have also connected a weak 110K pullup to the alert pin.  The bq34z100 contains bq34z100_R0_V0_06_BLD_0006 firmware.

Is there indeed a problem that effects only some of the alert flags or Am I missing something in the configuration?

Rob

  • 0
    TI__Expert 6470 points

    Hi Rob,

    My testing confirms your discovery. Looks like the alert register was not implemented as defined and documented. You can click on the words "Alert Configuration" on the dataflash screen of the EVSW and a graphic will appear showing which of the flag bits can be routed to the Alert pin. Apparently, the ones marked as RSVD are not working. I don't yet understand how this could have happened, since the firmware goes through extensive testing of every feature prior to release. We will investigate and decide whether to update the firmware or the documentation.

    Our apologies, and thanks for your effort involved in bringing this to our attention.

    Regards,

    Doug

  • 0 in reply to Doug Williams4811
    Prodigy 40 points

    I see a new datasheet was posted on Decemeber 7th, 2012 but I see no changes in the alert pin operation description.  I'll assume this means a new firmware SENC file is available that fixes the alert pin operation to act as described in the datasheet.  Could you provide a link to the new SENC firmware file.

    Thanks,

    Rob

  • 0 in reply to Rob D
    TI__Expert 6470 points

    Rob,

    We are planning to release a new "R1" version of the gauge to fix this issue, but a date has not been set. Please contact Tim Starr for more details.

    Doug

  • 0 in reply to Doug Williams4811
    Prodigy 10 points

    Dear Rob,

    you wrote "I have also connected a weak 110K pullup to the alert pin" referring to P2 (pin1).
    Can you confirm it?
    I'm a little bit confused because after some checks seems you are right (so P2 is used like an open collector when it is used as an alarm),
    but in the other hand it is also a "push pull" pin when it is used to drive ON the FET that control the "LED B" in case of 4 LED Mode.

    I suppose this is the same for P4, P5 and P6 (when they are used as an alert), correct?
    In the "sluu904", in the EVA board, seems that the pullup for P6 is the NTC, correct me if I'm wrong...
    Thanks

    Fabio