SLUUCY8 December 2023 BQ77307
The TS pin on the BQ77307 device can be used to implement cell temperature protections with a thermistor connected from the TS pin to VSS, if the Settings:Configuration:TS Mode[TSMODE] bit is set. In this mode, the pin is internally connected to a 20-kΩ trimmed pullup resistor, which is biased by the internal 1.8V LDO (REG18) voltage. The voltage at the TS pin is compared to a programmed threshold which is also based on the same 1.8 V LDO voltage used for the pullup resistor, thereby implementing a ratiometric evaluation.
When the TS pin is configured for thermistor temperature protection, the device enables the internal pullup resistor only while the pin voltage is being evaluated during each CHECK interval (which is the default recommended setting). Alternatively, the pullup resistor can be biased continuously by sending the 0x69 REGOUT_CONTROL() command with the [TS_ON] bit set.