BQ28550-R1 Datasheet, PDF (25/42 Pages) Texas Instruments – Single Cell Li-Ion Battery Gas Gauge

Not Recommended for New Designs
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bq28550-R1
SLUSAS4A – OCTOBER 2012 – REVISED SEPTEMBER 2014
Table 7. Standard Commands (continued)
Name
Command Code
DeviceName()
0x21
DeviceChemistry()
0x22
ManufacturerData()
0x23
Authenticate()
0x2f
CellVoltage1()
0x3f
Extended SBS Data Commands
OperationStatus()
0x54
ChargingStatus()
0x55
UnSealKey()
0x60
FullAccessKey()
0x61
AuthenKey0()
0x63
AuthenKey1()
0x64
AuthenKey2()
0x65
AuthenKey3()
0x66
ManufacturerInfo()
0x70
SenseResistor()
0x71
Temperature()
0x72
ManufacturerStatus()
0xB1
Min Value
—
—
—
—
0
0x0000
0x0000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
0x00000000
—
0
0x0000
Max Value
—
—
—
—
65535
Default value
bq28550-R1
LION
—
—
—
0xffff
—
0xffff
—
0xffffffff
—
0xffffffff
—
0xffffffff
—
0xffffffff
—
0xffffffff
—
0xffffffff
—
—
—
65535
—
0xffff
—
—
Units
ASCII
ASCII
ASCII
ASCII
mV
0xf7f7
—
—
—
—
—
—
—
ASCII
µΩ
—
—
Sealed Access
R/W
R/W
R/W
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
7.6.5.7.2 Run-Time-to-Empty
Battery pack run-time-to-empty can be calculated using the following method—the host system reads and stores
the following information during a discharge period and averages the data over a user-determined period of time:
• The DSG bit of the BatteryStatus register is set to ensure DOUT terminal is high (ensure the system is in
discharge mode).
• AverageCurrent (mA)
– Positive value = Charge Current
– Negative value = Discharge Current
– One minute rolling average of current value (the user can accumulate this time for improved granularity)
• RemainingCapacity (mAh)
Run-Time-to-Empty = RemainingCapacity (avg mAh) ÷ AverageCurrent (mA). This result will be in hours, and
therefore to convert to minutes, divide the results by 60.
7.6.5.7.3 Charging Time To Full
This is a read-only function that predicts the remaining time until battery reaches full charge in minutes based on
Average Current(). The computation accounts for the taper current time extension from the linear TTF
computation based on a fixed Average Current() rate of change of accumulation. A value of 65,535 indicates a
battery is NOT being charged.
7.6.5.7.4 Remaining Capacity Alert
To set a notification when battery capacity is below a pre-determined value, the user can set a Remaining
Capacity alarm alert in the system side. The Remaining Capacity value determined by the bq28550-R1 device is
compared to the user-selected value. If the Remaining Capacity value < the user-selected Remaining Capacity
threshold, the host system should instruct the user on what action is needed.
Copyright © 2012–2014, Texas Instruments Incorporated
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