SBAS475A June 2009 – January 2023 AMC6821-Q1
PRODUCTION DATA
The remote temperature sensor failure detection determines whether the remote sensor diode has an open-circuit condition, a short-circuit to ground, or a short-circuit (IN+) to (IN–) condition. This fault detection is based on the analog input voltage and is not checked until the first monitoring cycle is completed after power-on.
Reading the fault sensor returns a value of –128°C (0x80). Since the power-on default value of the temperature data registers is 0x80 (–128°C), a reading of 0x80 from the temperature data register immediately after power-on does not indicate a diode fault condition. The remote temperature sensor failure is only checked after the first monitoring cycle has been completed after power-on or reset.
When a remote sensor failure occurs, the remote sensor failure bit (RTF in the Status Register) is set to '1', the OVR pin is forced low, and if the interrupt is enabled (RTFIE = 1), the RTF interrupt is generated through the SMBALERT pin. Once this interrupt is generated, the RTF bit remains '1' and the OVR pin stays low until a power-on reset or software reset is issued, whether or not the failure condition persists.