BQ2040SN-C408 BENCHMARQ, BQ2040SN-C408 Datasheet - Page 16

• Manufacturer Part Number: BQ2040SN-C408
• Description: BATTERY CHARGE MONITOR, SMD, 2040
• Manufacturer: BENCHMARQ

Specifications of BQ2040SN-C408

• Battery Management Function: Charger, Status Monitor
• Battery Type: Li-Ion / NiCd / NiMH
• Supply Voltage Range: 3V To 6.5V
• Battery Ic Case Style: SOIC
• No. Of Pins: 16
• Operating Temperature Range: 0°C
• Interface Type: 2-Wire, Serial

bq2040
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).
ChargingCurrent() (0x14)
If enabled, the bq2040 sends the desired charging rate in
mA to the Smart Battery Charger.
ChargingVoltage() (0x15)
If enabled, the bq2040 sends the desired voltage in mV
to the Smart Battery Charger.
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.
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.
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.
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.
16
BatteryStatus() (0x16)
This read-only word returns the battery status word.
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.
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 status reg-
ister with alarm conditions bitmapped as shown in
Table 5.
Output: unsigned integer. Returns the count of
charge/discharge cycles the battery has
experienced.
Units: cycles
0x0000-
0x8000
0x4000
0x2000
0x1000
0x0800
0x0400
0x0200
0x0100
0x0080
0x0040
0x0020
0x0010
0x000f
Table 5. Status Register
Over_Charged_Alarm
Terminate_Charge_Alarm
Reserved
Over_Temp_Alarm
Terminate_Discharge_Alarm
Reserved
Remaining_Capacity_Alarm
Remaining_Time_Alarm
Initialized
Discharging
Fully_Charged
Fully_Discharged
Reserved for error codes
Status Bits
Error Code
Alarm Bits