SFFS141 December   2021 TCAN1167-Q1

 

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5.3.1.1 SM-1: CAN bus fault diagnostics

The TCAN1167-Q1 provides advanced bus fault detection. The device can determine certain fault conditions and set a status/interrupt flag so that the MCU can understand what the fault is. Detection takes place and is recorded if the fault is present during four dominant to recessive transitions with each dominant bit being > 1.5 us. As with any bus architecture where terminantion resistors are at each end not every fault can be specified to the lowest level, meaning exact location. The fault detection circuitry is monitoring the CANH and CANL pins (currents) to determine if there is a short to battery, short to ground, short to each other or opens. From a system perspective, the location of the device also determines what can be detected. See device datasheet for detailed description of the CAN bus fault diagnostic.