BQ2040_15 Datasheet, PDF (16/36 Pages) Texas Instruments – Gas Gauge IC With SMBus Interface

Not Recommended For New Designs
bq2040
Output: unsigned integer. Returns the minutes of
operation left.
Units: minutes
Range: 0 to 65,534min
Granularity: 2min or better
Invalid data indication: 65,535 indicates battery
is not being discharged.
AverageTimeToFull() (0x13)
This read-only word returns the predicted time until the
Smart Battery reaches full charge at the present aver-
age charge rate (minutes).
Output: unsigned integer. Returns the remaining
time in minutes to full.
Units: minutes
Range: 0 to 65,534min
Granularity: 2min or better
Invalid data indication: 65,535 indicates battery
is not being charged.
ChargingCurrent() (0x14)
If enabled, the bq2040 sends the desired charging rate in
mA to the Smart Battery Charger.
Output: unsigned integer. Transmits/returns the
maximum charger output current in mA.
Units: mA
Range: 0 to 65,534mA
Granularity: 0.2% of the design capacity or better
Invalid data indication: 65,535 indicates that the
Smart Charger should operate as a voltage source
outside its maximum regulated current range.
ChargingVoltage() (0x15)
If enabled, the bq2040 sends the desired voltage in mV
to the Smart Battery Charger.
Output: unsigned integer. Transmits/returns the
charger voltage output in mV.
Units: mV
Range: 0 to 65,534mV
Granularity: 0.2% of the DesignVoltage or better
Invalid data indication: 65,535 indicates that the
Smart Battery Charger should operate as a cur-
rent source outside its maximum regulated voltage
range.
BatteryStatus() (0x16)
This read-only word returns the battery status word.
Output: unsigned integer. Returns the status reg-
ister with alarm conditions bitmapped as shown in
Table 5.
Some of the BatteryStatus flags (Remaining_Capac-
ity_Alarm and Remaining_Time_Alarm) are calculated
based on current. See Table 8 and 9 for definitions.
Table 5. Status Register
0x8000
0x4000
0x2000
0x1000
0x0800
0x0400
0x0200
0x0100
0x0080
0x0040
0x0020
0x0010
0x0000-
0x000f
Alarm Bits
Over_Charged_Alarm
Terminate_Charge_Alarm
Reserved
Over_Temp_Alarm
Terminate_Discharge_Alarm
Reserved
Remaining_Capacity_Alarm
Remaining_Time_Alarm
Status Bits
Initialized
Discharging
Fully_Charged
Fully_Discharged
Error Code
Reserved for error codes
CycleCount() (0x17)
This read-only word returns the number of charge/dis-
charge cycles the battery has experienced. A charge/dis-
charge cycle starts from a base value equivalent to the
battery's state-of-charge on completion of a charge cycle.
The bq2040 increments the cycle counter during the cur-
rent charge cycle if the battery has been discharged 15%
below the state-of-charge at the end of the last charge cy-
cle. This prevents false reporting of small charge/discharge
cycles. The cycle count is stored in EEPROM within
400ms of an update.
Output: unsigned integer. Returns the count of
charge/discharge cycles the battery has
experienced.
Units: cycles
16