BQ27510-G2 Datasheet, PDF (20/38 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge With Direct Battery Connection

bq27510-G2
SLUS948 – AUGUST 2010
www.ti.com
Load Select
Load Select defines the type of power or current model to be used to compute load-compensated capacity in the
Impedance Track™ algorithm. If Load Mode = 0 (Constant Current), then the options presented in Table 8 are
available.
LoadSelect
Value
0
1(default)
2
3
4
5
6
Table 8. Constant-Current Model Used When Load Mode = 0
Current Model Used
Average discharge current from previous cycle: There is an internal register that records the average discharge current
through each entire discharge cycle. The previous average is stored in this register.
Present average discharge current: This is the average discharge current from the beginning of this discharge cycle
until present time.
Average current: based off the AverageCurrent( )
Current: based off of a low-pass-filtered version of AverageCurrent( ) (t=14s)
Design capacity / 5: C Rate based off of Design Capacity /5 or a C / 5 rate in mA.
AtRate (mA): Use whatever current is in AtRate( )
User_Rate-mA: Use the value in User_Rate( ). This gives a completely user-configurable method.
If Load Mode = 1 (Constant Power) then the following options are available:
LoadSelect
Value
0(default)
1
2
3
4
5
6
Table 9. Constant-Power Model Used When Load Mode = 1
Current Model Used
Average discharge power from previous cycle: There is an internal register that records the average discharge power
through each entire discharge cycle. The previous average is stored in this register.
Present average discharge power: This is the average discharge power from the beginning of this discharge cycle until
present time.
Average current × voltage: based off the AverageCurrent( ) and Voltage( ).
Current × voltage: based off of a low-pass-filtered version of AverageCurrent( ) (t=14s) and Voltage( ).
Design energy / 5: C Rate based off of Design Energy /5 or a C / 5 rate in mA.
AtRate (10 mW): Use whatever current is in AtRate( )
User_Rate-10 mW: Use the value in User_Rate( ) mW. This gives a completely user-configurable method.
Reserve Cap-mAh
Reserve Cap-mAh determines how much actual remaining capacity exists after reaching 0
RemainingCapacity( ), before Terminate Voltage is reached.
Reserve Cap-mWh
Reserve Cap-mWh determines how much actual remaining capacity exists after reaching 0 AvailableEnergy( ),
before Terminate Voltage is reached.
Dsg Current Threshold
This register is used as a threshold by many functions in the bq27510-G2 to determine if actual discharge current
is flowing into or out of the cell. The default for this register is 60 mA which should be sufficient for most
applications. This threshold should be set low enough to be below any normal application load current but high
enough to prevent noise or drift from affecting the measurement.
Chg Current Threshold
This register is used as a threshold by many functions in the bq27510-G2 to determine if actual charge current is
flowing into or out of the cell. The default for this register is 75 mA which should be sufficient for most
applications. This threshold should be set low enough to be below any normal charge current but high enough to
prevent noise or drift from affecting the measurement.
20
Submit Documentation Feedback
Copyright © 2010, Texas Instruments Incorporated