ZHCSJK5B January 2018 – November 2019 TCAN4550-Q1
This is a device preservation event. If the junction temperature of the device exceeds the thermal shut down threshold, the device turns off the internal 5 V LDO for the CAN transceiver thus blocking the signal to bus transmission path as well as turning of the ability to source current and voltage to the VCCOUT pin. A thermal shut down interrupt flag is set and an interrupt is inserted so that the microprocessor is informed. If this event happens, other interrupt flags may be set as an example a bus fault where the CAN bus is shorted to Vbat. When this happens the digital core and SPI interface are still active. After a time of ≈ 300 ms the device checks the temperature of the junction. The thermal shutdown (TSD) timer starts when TSD fault event starts and exits to standby mode when a TSD fault is not present when the TSD timer is expired. While in thermal shut down protected mode a SPI write to change the device to either Normal or Standby mode is ignored while writes to change to sleep mode is accepted.
If a thermal shut down event happens while the device is experiencing a VIO under voltage event the device enters sleep mode.