BQ2085-V1P2 Datasheet, PDF (15/56 Pages) Texas Instruments – SBS-COMPLIANT GAS GAUGE IC FOR USE WITH THE bq29311

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bq2085−V1P2
SLUS590 − DECEMBER 2003
D Overcharge: An overcharge condition exists if the battery is charged more than the Maximum Overcharge value
after RM = FCC. Maximum Overcharge is programmed in DF 0x4e-0x4f. On detecting an overcharge condition,
the bq2085−V1P2 sets the ChargingCurrent( ) to zero and sets the OVER_CHARGED_ALARM,
TERMINATE_CHARGE_ ALARM, and FULLY_CHARGED bits in BatteryStatus( ). The bq2085−V1P2 clears
the TERMINATE_CHARGE_ ALARM when it detects that the battery is no longer being charged and clears the
OVER_CHARGED_ALARM when 2mAh of discharge are measured. The FULLY_CHARGED bit remains set
and the bq2085−V1P2 continues to broadcast zero charging current until RelativeStateOfCharge( ) is less than
Fully Charged Clear% programmed in DF 0x47. The counter used to track overcharge capacity is reset with 2
mAh of discharge.
D Undertemperature: An undertemperature condition exists if Temperature( ) < 0°C. On detecting an under
temperature condition, the bq2085−V1P2 sets ChargingCurrent( ) to zero. The bq2085−V1P2 sets
ChargingCurrent( ) to the appropriate precharge rate or fast-charge rate when Temperature( ) ≥ 0°C.
Primary Charge Termination
The bq2085−V1P2 terminates charge if it detects a charge-termination condition based on current taper. A
charge-termination condition includes the following:
For current taper, ChargingVoltage( ) must be set to the pack voltage desired during the constant-voltage phase
of charging. The bq2085−V1P2 detects a current taper termination when the pack voltage is greater than or equal
to ChargingVoltage( ) minus Current Taper Qual Voltage in DF 0x4a and the charging current is below a threshold
determined by Current Taper Threshold in DF 0x48−0x49 and above 22.5 mA for two consecutive 40-second
intervals.
Once the bq2085−V1P2 detects a Primary Charge Termination, the bq2085−V1P2 sets the
TERMINATE_CHARGE_ALARM and FULLY_CHARGED bits in BatteryStatus( ), and sets the
ChargingCurrent( ) to the maintenance charge rate as programmed in Maintenance Charging Current DF 0x3f,
0x40. On termination, the bq2085−V1P2 also sets RM to a programmed percentage of FCC, provided that
RelativeStateOfCharge( ) is below the desired percentage of FCC and the CSYNC bit in Gauge Configuration DF
0x29 is set. The programmed percentage of FCC, Fast Charge Termination %, is set in DF 0x46. The
bq2085−V1P2 clears the FULLY_CHARGED bit when RelativeStateOfCharge( ) is less than the programmed
Fully Charged Clear %. The bq2085−V1P2 broadcasts the fast-charge rate when the FULLY_CHARGED bit is
cleared and voltage and temperature permit. The bq2085−V1P2 clears the TERMINATE_CHARGE_ALARM
when it no longer detects that the battery is being charged or it no longer detects the termination condition. See
Table 6 for a summary of BatteryStatus( ) alarm and status bit operation.
Table 6. Alarm and Status Bit Summary
BATTERY STATE
CONDITIONS
Overcurrent
Prolonged
Overcurrent
Overload
C( ) ≥ CC( ) + Overcurrent Margin
AC( ) ≥ Fast-Charging Current +
Overcurrent Margin
AC( ) ≤ −Overload Current
Overvoltage
V( ) ≥ CV( ) + Over Voltage Margin
VCELL1, 2, 3, or 4 ≥ Cell Over Voltage
Overtemperature T( ) ≥ Max Temperature
Overcharge
Capacity added after RM( ) = FCC( ) ≥
Maximum Overcharge
T( ) < 0°C
Undertemperature
0°C ≤ T( ) < LTF
CC( ) CURRENT AND
STATUS BITS SET
CC( ) = 0, TCA = 1
CVOV = 1
CC( ) = 0, TCA = 1
CVUV = 1
TCA = 1
CC( ) = 0, CVOV = 1
CC( ) = 0, OTA = 1,
TCA = 1, CVOV = 1
CC( ) = 0, FC = 1
OCA = 1, TCA = 1
CC( ) = 0
CC( ) = Precharge
STATUS CLEAR CONDITION
C( ) < Overcurrent Margin
AC( ) < 256 mA
AC( ) < –256 mA
DISCHARGING = 1
V( ) < CV( ) + Over Voltage Margin
VCELL(all) ≤ Cell Over Voltage Reset
T( ) ≤ Max Temperature −Temperature
Hysteresis or T( ) ≤ 43°C
RSOC( )< Fully Charged Clear %
DISCHARGING = 1, and 2 mAh of
discharge is measured
0°C ≤ T( )
T( ) ≥ LTF + DF 0x44 (default = 3°C)
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