BQ27425-G2_15 Datasheet, PDF (11/39 Pages) Texas Instruments – Fuel Gauge With Integrated Sense Resistor

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bq27425-G2
SLUSB23B – OCTOBER 2012 – REVISED JUNE 2015
Feature Description (continued)
8.3.2.1 SOC Smoothing Feature
Rapid changes in operating conditions, such as temperature or discharge current, can lead to sudden changes in
the algorithm's immediate calculation of RemainingCapacity( ), FullChargeCapacity( ), and StateOfCharge( ).
SOC Smoothing provides filtered data to the host resulting in more gradual changes to SOC-related data when
conditions vary and can provide a better end-user experience. The feature is enabled through Op Config
[SMOOTHEN].
8.3.3 GPOUT Pin
The GPOUT pin is a multiplexed pin and the polarity of the pin output can be selected through the [GPIO_POL]
bit of the Operation Configuration. The function is defined by Op Config [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 fuel gauge has two flags accessed by the Flags( ) function that warn when the
battery 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 GPOUT pin automatically reflects the status of the
[SOC1] flag when Op Config [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 1-ms pulse width under various conditions
as described in Table 1.
ENABLE
CONDITION
Change in
SOC
(SOCI Delta) ≠ 0
State Change (SOCI Delta) ≠ 0
Battery
Removal
[BIE] bit is set in Op
Config
Table 1. SOC_INT Function Definition
PULSE
WIDTH
1 ms
1 ms
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.
1 ms
When battery removal is detected by the BIN pin.
8.3.4 Battery Detection (BIN)
The function of Op Config [BIE] bit is described in the Table 2. When battery insertion is detected and
INITIALIZATION mode is completed, the fuel gauge transitions to NORMAL mode to start Impedance Track™
fuel gauging. When battery insertion is not detected, the fuel gauge remains in INITIALIZATION mode.
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