SLUUBY1B December 2020 – April 2022 BQ76942
The BQ76942 device integrates an Overtemperature FET (OTF) Protection that triggers an alert or fault when the FET temperature is greater than or equal to a programmable threshold TOTF. The TOTF threshold is programmable from 0°C to 150°C in 1°C steps using the Protections:OTF:Threshold configuration register. The OTF protection is enabled using the Settings:Protection:Enabled Protections B:[OTF] configuration bit.
The OTF protection triggers an alert signal when an overtemperature FET event is first detected, then will trigger a fault after a programmable detection delay, OTF_DLY, which can be set from 0-sec to 255-sec in units of 1-sec. The delay is set by the Protections:OTF:Delay configuration register.
When an OTF fault is triggered, the device will turn off the DSG FET, the CHG FET, or both FETs if configured for autonomous FET control, based on settings in Settings:Protection:DSG FET Protections B[OTF] and Settings:Protection:CHG FET Protections B[OTF]. The device will recover (if configured for autonomous recovery) when the temperature is less than or equal to the threshold set by Protections:OTF:Recovery for Protections:Recovery:Time duration.
The temperature used by the OTF protection is the maximum of all temperature readings that are designated for FET temperature, and can include the internal temperature measurement as well as all external thermistors which are enabled.