SLUUCD5 January 2023 BQ27427
The GPOUT pin is a multiplexed pin and the polarity of the pin output can be selected via the OpConfig[GPIO_POL] bit. The function is defined by the OpConfig [BATLOWEN] bit. If the bit is set, the Battery Low Indicator (BAT_LOW) function is selected for the GPOUT pin. If it is cleared, the SOC interrupt (SOC_INT) function is selected for the GPOUT pin.
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 warns when the battery SOC has fallen to critical levels. When StateOfCharge() falls below the first capacity threshold, specified in SOC1 Set Threshold, the [SOC1] 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 [BATLOWEN] = 1 and [GPIOPOL] = 1. The polarity can be flipped by setting [GPIOPOL] = 0.
When StateOfCharge() falls below the second capacity threshold, SOCF Set Threshold, the [SOCF] 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 a 1-ms pulse width under various conditions as described in #GUID-B585277E-050C-4675-85F1-1A166D15054A/SLUSAF41115.
| Enable Condition | Pulse Width | Description | |
|---|---|---|---|
| Change in SOC | (SOCI Delta) ≠ 0 | 1 ms | 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%. |
| State Change | (SOCI Delta) ≠ 0 | 1 ms | Upon detection of entry to a charge or a discharge state. Relaxation is not included. |
| Battery Removal | OpConfig [BIE] bit is set. | 1 ms | When battery removal is detected by the BIN pin. |
| Initialization Complete | Always | 1 ms | After initial gauge predictions are updated upon exit from POR, the ControlStatus() [INITCOMP] bit is set. |
| PULSE_SOC_INT command | Subcommand | 1 ms | Instructs the fuel gauge to pulse the GPOUT pin for approximately 1 ms with 1 second of receiving the command. Mostly used for debug purposes. |