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Original question:

BQ27750: Over Temperature Charge not changing OperationStatus()[XCHG]

BQ34Z100-G1: BQ34Z100-G1: Over and Under Temperature Charge not changing flag XCHG or CHG_INH

Robert Charnock
Prodigy 60 points
Part Number: BQ34Z100-G1

Hi,

When the Charge current is over Chg Current Threshold and either over Chg Inhibit Temp High or under Chg Inhibit Temp Low ,  XCHG and CHG_INH never change they are (0).

When the Charge current is under Chg Current Threshold and either over Chg Inhibit Temp High or under Chg Inhibit Temp Low , CHG_INH does change to a (1).

Is there something that is needed to enable this feature to work?

According to document SLUA664 sections 2.2 and 2.3 this should work.

Chg Inhibit Temp Low = 0 C
Chg Inhibit Temp High = 40 C
Temp Hys = 5 C

Chg Current Threshold = 50mA

Thank you for your help

  • 0
    TI__Mastermind 42535 points
    We have an engineer looking into this. You will get a reply here before the week ends.
  • 0
    TI__Mastermind 25955 points
    Hi Robert,

    Working on replicating the results in the lab. Will update by Friday at the latest.

    Please send the SREC and a log of the event so I can compare the results. Thank you!

    Sincerely,
    Bryan Kahler
  • 0 in reply to Robert Charnock
    TI__Mastermind 25955 points
    Hi Robert,

    Thank you for the files - still on track to provide an update by Friday at the latest.

    Sincerely,
    Bryan Kahler
  • 0 in reply to Bryan Kahler
    TI__Mastermind 25955 points
    Hi Robert,

    Please try increasing the the OT Chg to be slightly lower than Suspend High Temp.

    Sincerely,
    Bryan Kahler
  • 0 in reply to Bryan Kahler
    Prodigy 60 points

    Hi Bryan,

    You response was a little confusing. OT Chg and Suspend High Temp are both currently set at 45 C.  To make OT Chg slightly lower I would have to decrease it.

    I decreased OT Chg to be below Suspend High Temp, no change.

    Then I tried to increase OT Chg to be above Suspend High Temp, no change.

     

     

    I did some more testing and found in order to have the XCHG flag become active the following had to be true:

     

    High Temps.

    “Suspend High Temp” had to be set lower than “Charge Inhibit High Temp”

    Current had to be less than the “Chg Current Threshold”.

     

    Example:

    Suspend High Temp = 35C

    Charge Inhibit High Temp = 45C

    Charge Inhibit hys = 5C

     

    Temp increased from 30 to 50 then decreased from 50 to 30.

    Temp increase >, Temp decrease <

    Temp    30>>>>35>>>>>40>>>>45>>>>50<<<<45<<<<40<<<<35<<<<30

    XCHG    000000011111111111110000000000000000001111110000000

    CHG_INH 000000000000000000001111111111111111110000000000000

     

    The only flag that works when the Current is greater than the “Chg Current Threshold” is the “OTC”.

     

    Low Temps.

    “Suspend Low Temp” had to be set higher than “Charge Inhibit Low Temp”

    Current had to be less than the “Chg Current Threshold”

     

    Example:

    Suspend Low Temp = 0C

    Charge Inhibit Low Temp = -10C

    Charge Inhibit hys = 5C

     

    Temp decreased from 5 to -15 then increased from -15 to 5.

    Temp increase >, Temp decrease <

    Temp    5<<<<0<<<<-5<<<<-10<<<<-15>>>>-10>>>>-5>>>>0>>>>5

    XCHG    0000011111111111110000000000000000000011111100000

    CHG_INH 0000000000000000001111111111111111111100000000000

     

    So far XCHG and CHG_INH flags have functioned as described in SLUA664, Configuring the bq34100 Data Flash.

     

    Does a better document exist describing the flag functions?

     

    One of our main goals was to use either the XCHG or CHG_INH flag to indicate when the battery pack would be outside the temperature range of 0 to 45 C while charging without having to poll the temperature register.

     

    Thanks for your help so far.

    Robert


  • 0 in reply to Robert Charnock
    TI__Mastermind 25955 points
    Hi Robert,

    Thank you for the continued and detailed discussion. Working on replication in the lab with the goal of providing better guidance to flag states - will update by Friday.

    Sincerely,
    Bryan Kahler
  • 0 in reply to Bryan Kahler
    TI__Mastermind 25955 points
    Hi Robert,

    Have replication of results on this end. Thank you for the discussion with respect to the goals. Working towards describing the flag functionality with the goal of not requiring polling. - will update by Tuesday.
  • 0 in reply to Bryan Kahler
    TI__Mastermind 25955 points
    Hi Robert,

    Update by Tuesday, as promised - have not yet found a flag or combination of flags to provide the requested functionality.

    Polling may be required during charging when outside of the temperature range.

    Sincerely,
    Bryan Kahler