BQ27425-G2_14 Datasheet, PDF (22/35 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge With Integrated Sense Resistor

bq27425-G2
SLUSB23A – OCTOBER 2012 – REVISED FEBRUARY 2013
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Battery Detection (BIN)
The function of OpConfig[BIE] bit is described in the Table 10 table below. When battery insertion is detected
and INITIALIZATION mode is completed, the bq27425 transitions to NORMAL mode to start Impedance Track™
fuel gauging. When battery insertion is not detected, the bq27425 remains in INITIALIZATION mode.
OpConfig[BIE]
1
0
Table 10. Battery Detection
Battery Insertion Requirement
(1) Host drives BIN pin from logic high to low
to signal battery insertion.
or
(2) A weak pull-up resistor can be used
(between BIN and VCC pin). When battery
pack with pull-down is connected, it can
generate a logic low to signal battery
insertion.
Host sends BAT_INSERT subcommand to
signal battery insertion.
Battery Removal Requirement
(1) Host drives BIN pin from logic low to high to
signal battery removal.
or
(2) When battery pack with pull-down is removed,
the weak pull-up resistor can generate a logic high
to signal battery removal.
Host sends BAT_REMOVE subcommand to signal
battery removal.
DETECTING CHARGE TERMINATION
The bq27425 detects charge termination when (1) AverageCurrent( ) < Taper Current (default = 75 mA) for 80
seconds, (2) during the same 80 seconds, the accumulated change in capacity > 0.25mAh / 40 seconds, and (3)
Voltage( ) > (Charging Voltage – 100mV). When this occurs, the Flags( )[CHG] bit is cleared. Also, if the
[RMFCC] bit of Operation Configuration is set, then RemainingCapacity( ) is set equal to
FullChargeCapacity( ).
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