BQ2085 Datasheet, PDF (27/56 Pages) Texas Instruments – SBS-COMPLIANT GAS GAUGE IC FOR USE WITH THE bq29311

bq2085
SLUS541 – OCTOBER 2002
Input/Output: Signed integer-charge or discharge; the AtRate( ) value is positive for charge, negative for
discharge, and zero for neither (default).
Units
Charge range
Discharge range
Granularity
Accuracy
BATTERY MODES
CAPACITY_MODE
BIT = 0
CAPACITY_MODE
BIT = 1
mA
10 mW
1 to 32,767 mA
1 to 32,767 10 mW
–1 to –32,768 mA
–1 to –32,768 10 mW
1 Unit
NA
AtRateTimeToFull( ) (0x05)
Description: Returns the predicted remaining time to fully charge the battery at the AtRate( ) value (mA).
Purpose: The AtRateTimeToFull( ) function is part of a two-function call-set used to determine the predicted
remaining charge time at the AtRate value in mA. The bq2085 updates AtRateTimeToFull( ) within 5 ms after
the SMBus host sets the AtRate value. The bq2085 automatically updates AtRateTimeToFull( ) based on the
AtRate( ) value every 1 s.
SMBus protocol: Read word
Output: Unsigned integer—predicted time in minutes to fully charge the battery.
Units: Minutes
Range: 0 to 65,534 min
Granularity: 2 min or better
Accuracy: ± MaxError( ) _* FullChargeCapacity( )/|AtRate( )|
Invalid Data Indication: 65,535 indicates the AtRate ≤ 0.
AtRateTimeToEmpty( ) (0x06)
Description: Returns the predicted remaining operating time if the battery is discharged at the AtRate( ) value.
Purpose: The AtRateTimeToEmpty( ) function is part of a two-function call-set used to determine the remaining
operating time at the AtRate( ) value. The bq2085 updates AtRateTimeToEmpty( ) within 5 ms after the SMBus
host sets the AtRate( ) value. The bq2085 automatically updates AtRateTimeToEmpty( ) based on the AtRate( )
value every 1 s.
SMBus protocol: Read word
Output: Unsigned integer—estimated operating time left.
Units: Minutes
Range: 0 to 65,534 min
Granularity: 2 min or better
Accuracy: -0,+MaxError( ) × FullChargeCapacity/|AtRate( )|
Invalid Data Indication: 65,535 indicates AtRate ≥ 0.
AtRateOK( ) (0x07)
Description: Returns a Boolean value that indicates whether or not the battery can deliver the AtRate( )value
of additional energy for 10 seconds. If the AtRate value is zero or positive, the AtRateOK( ) function ALWAYS
returns OK (logic 1).
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