BQ2085 Datasheet, PDF (32/56 Pages) Texas Instruments – SBS-COMPLIANT GAS GAUGE IC FOR USE WITH THE bq29311

bq2085
SLUS541 – OCTOBER 2002
Granularity: 2 minutes or better
Accuracy: –0, +MaxError( ) _* FullChargeCapacity( ) / AverageCurrent( )
Invalid Data Indication: 65,535 indicates the battery is not being charged.
ChargingCurrent( ) (0x14)
Description: Returns the desired charging rate in mA.
Purpose: The ChargingCurrent( ) function sets the maximum charge current of the battery. The
ChargingCurrent( ) value should be used in combination with the ChargingVoltage( ) value to set the charger’s
operating point. Together, these functions permit the bq2085 to dynamically control the charging profile
(current/voltage) of the battery. The bq2085 can effectively turn off a charger by returning a value of 0 for this
function. The charger may be operated as a constant-voltage source above its maximum regulated current
range by returning a ChargingCurrent( ) value of 65,535.
SMBus protocol: Read word
Output: Unsigned integer—maximum charger output current in mA.
Units: mA
Range: 0 to 65,535 mA
Granularity: 1 mA
Accuracy: Not applicable
Invalid Data Indication: 65,535 indicates that a charger should operate as a voltage source outside its
maximum regulated current range.
ChargingVoltage( ) (0x15)
Description: Returns the desired charging voltage in mV.
Purpose: The ChargingVoltage( ) function sets the maximum charge voltage of the battery. The
ChargingVoltage( ) value should be used in combination with the ChargingCurrent( ) value to set the charger’s
operating point. Together, these functions permit the bq2085 to dynamically control the charging profile
(current/voltage) of the battery. The charger may be operated as a constant-current source above its maximum
regulated voltage range by returning a ChargingVoltage( ) value of 65,535.
SMBus protocol: Read word
Output: Unsigned integer—charger output voltage in mV.
Units: mV
Range: 0 to 65,535 mV
Granularity: 1mV
Accuracy: Not applicable
Invalid Data Indication: 65,535 indicates the charger should operate as a current source outside its maximum
regulated voltage range.
BatteryStatus( ) (0x16)
Description: Returns the bq2085 status word (flags). Some of the BatteryStatus( ) flags
(REMAINING_CAPACITY_ALARM and REMAINING_TIME_ALARM) are calculated on the basis of either
current or power depending on the setting of the BatteryMode( ) CAPACITY_MODE bit. This is important
because use of the wrong calculation mode may result in an inaccurate alarm.
Purpose: The BatteryStatus( ) function is used by the power-management system to get alarm and status bits,
as well as error codes from the bq2085. This is basically the same information broadcast to both the SMBus
host and the smart battery charger by the AlarmWarning( ) function except that the AlarmWarning( ) function
sets the error code bits all high before sending the data.
SMBus protocol: Read word
32
www.ti.com