SLUUBD4A April 2016 – November 2022 BQ27220
This fuel gauge has several pin-function configurations available for the end application. Each configuration is assigned a pin function code, or PFC, specified by the Operation Config A [PFC_CFG1, PFC_CFG0] bits (see Table 5-4). If the fuel gauge is configured to measure external temperature via the Operation Config A [TEMPS] bit, a voltage bias of approximately 125 ms is applied periodically to the external thermistor network in order to make a temperature measurement.
PFC | PFC_CFG [1:0] | External Thermistor Bias Rate ([TEMPS] = 1 only) | BAT_GD Pin Usage for PFC | Pin Function Description | ||
---|---|---|---|---|---|---|
Discharge | Charge | Sleep | ||||
0 | 00 | 1/s | 1/s | 1/20 s | NA | A dedicated external thermistor is used for the fuel gauge to monitor battery temperature in all conditions. The BAT_GD pin is not used to interface with a charger IC. |
1 | 01 | Temperature- based Charge Inhibit | A dedicated external thermistor is used for the fuel gauge to monitor battery temperature in all conditions. If battery charging temperature falls outside of the preset range defined in data memory, a charger can be disabled via the BAT_GD pin until cell temperature recovers. See Section 5.4.2, Charge Inhibit, for additional details. | |||
2 | 10 | None | NA | A shared external thermistor is supported between the fuel gauge and a charger IC; however, the BAT_GD pin is not used to interface with the charger IC. The fuel gauge biases the thermistor for battery temperature measurement and BAT INSERT CHECK mode (if Operation Config B [BIEnable] bit = 1) under discharge and relaxation conditions only so the charger IC can separately bias the thermistor during CHARGE mode. Bias networks required by the fuel gauge and the charger for the thermistor must be identical. | ||
3 | 11 | 1/s | Follows BatteryStatus()[FC] flags bit | Disables a battery charger IC when fuel gauge has determined the battery is fully charged. The BAT_GD pin reflects the logical status of the BatteryStatus()[FC] bit and is typically connected directly to the charger Charge Enable/Disable (CE/CD) pin or via a network to drive the charger Temperature Sense (TS) pin. |