BQ27425-G2_14 Datasheet, PDF (21/35 Pages) Texas Instruments – System-Side Impedance Track™ Fuel Gauge With Integrated Sense Resistor

bq27425-G2
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DETAILED PIN DESCRIPTIONS
SLUSB23A – OCTOBER 2012 – REVISED FEBRUARY 2013
GPOUT Pin
The GPOUT Pin is a multiplex pin and the polarity of the pin output can be selected via the [GPIO_POL] bit of
the Operation Configuration. The function is defined by [BATLOWEN]. If set, the Battery Low Indicator
(BAT_LOW) function for GPOUT pin is selected. If cleared, the SOC interrupt (SOC_INT) function is selected for
GPOUT.
When the BAT_LOW function is activated, the signaling on the multiplexed pin follows the status of the [SOC1]
bit in the Flags( ) register. The bq27425 has two flags accessed by the Flags( ) function that warns when the
battery’s SOC has fallen to critical levels. When StateOfCharge( ) falls below the first capacity threshold,
specified in SOC1 Set Threshold, the [SOC1] (State of Charge Initial) flag is set. The flag is cleared once
StateOfCharge( ) rises above SOC1 Set Threshold. The bq27425’s GPOUT pin automatically reflects the status
of the [SOC1] flag when OpConfig[BATLOWEN=0].
When StateOfCharge( ) falls below the second capacity threshold, SOCF Set Threshold, the [SOCF] (State of
Charge Final) flag is set, serving as a final discharge warning. Similarly, when StateOfCharge( ) rises above
SOCF Clear Threshold and the [SOCF] flag has already been set, the [SOCF] flag is cleared.
When the SOC_INT function is activated, the GPOUT pin generates 1ms pulse width under various conditions as
described in Table 9.
Change in
SOC
Enable Condition
(SOCI Delta) ≠ 0
State Change (SOCI Delta) ≠ 0
Battery
Removal
[BIE] bit is set in
OpConfig
Table 9. SOC_INT Function Definition
Pulse Width
1ms
1ms
1ms
Description
During charge, when the SOC is greater than (>) the points, 100% - n × (SOCI
Delta) and 100%;
During discharge, when the SOC reaches (≤) the points 100% - n × (SOCI Delta)
and 0%;
where n is an integer starting from 0 to the number generating SOC no less than
0%
Examples:
For SOCI Delta = 1% (default), the SOC_INT intervals are 0%, 1%, 2%, ….. 99%,
and 100%.
For SOCI Delta = 10%, the SOC_INT intervals are 0%, 10%, 20%, ….. 90%, and
100%.
Upon detection of entry to a charge or a discharge state.. Relaxation is not
included.
When battery removal is detected by BIN pin.
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