BQ2085 Datasheet, PDF (24/56 Pages) Texas Instruments – SBS-COMPLIANT GAS GAUGE IC FOR USE WITH THE bq29311

bq2085
SLUS541 – OCTOBER 2002
RemainingTimeAlarm( ) (0x02)
Description: Sets or gets the Remaining Time Alarm value. Whenever the AverageTimeToEmpty( ) falls below
the remaining time value, the bq2085 sends AlarmWarning( ) messages to the SMBus host with the
REMAINING_TIME_ALARM bit set. A remaining time value of 0 effectively disables this alarm. The bq2085
initially sets the remaining time value to the Remaining Time Alarm value programmed in DF 0x00–0x01. The
remaining time value remains unchanged until altered by the RemainingTimeAlarm( ) function.
Purpose: The RemainingTimeAlarm( ) function can be used by systems that want to adjust when the remaining
time alarm warning is sent. The remaining time value can be read to verify the value in use by the bq2085
RemainingTimeAlarm( ).
SMBus protocol: Read or write word
Input/Output: Unsigned integer—the point below which remaining time messages are sent.
Units: Minutes
Range: 0 to 65,535 minutes
Granularity: Not applicable
Accuracy: See AverageTimeToEmpty( ).
BatteryMode( ) (0x03)
Description: Selects the various battery operational modes and reports the battery’s mode and requests.
Defined modes include
D Whether the battery capacity information is specified in units of mAh or 10 mWh (CAPACITY_MODE bit)
D Whether the ChargingCurrent( ) and ChargingVoltage( ) values are broadcast to the smart battery charger
when the CHARGER_MODE bit is set.
D Whether all broadcasts to the smart battery charger and host are disabled
The defined request condition is the battery requesting a conditioning cycle (RELEARN_FLAG).
Purpose: The CAPACITY_MODE bit allows power management systems to best match their electrical
characteristics with those reported by the battery. For example, a switching power supply represents a constant
power load, whereas a linear supply is better represented by a constant current model. The CHARGER_MODE
bit allows a SMBus host or smart battery charger to override the smart battery desired charging parameters by
disabling the bq2085 broadcasts. The RELEARN_FLAG bit allows the bq2085 to request a conditioning cycle.
SMBus protocol: Read or write word
Input/Output: Unsigned integer—bit mapped— see below.
Units: Not applicable
Range: 0-1
Granularity: Not applicable
Accuracy: Not applicable
The BatteryMode( ) word is divided into two halves, the MSB (bits 8-15) which is read/write and the LSB (bits
0-7) which is read only. The bq2085 forces bits 0-6 to zero and prohibits writes to bit 7.
Table 12 summarizes the meanings of the individual bits in the BatteryMode( ) word and specifies the default
values, where applicable, are noted.
INTERNAL_CHARGE_CONTROLLER bit is not used by the bq2085.
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