SLLA651 April   2025 TCAN2845-Q1 , TCAN2847-Q1 , TCAN2855-Q1 , TCAN2857-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Device States
    1. 2.1 Init Mode
    2. 2.2 Restart Mode
    3. 2.3 Standby Mode
    4. 2.4 Normal Mode
    5. 2.5 Sleep Mode
    6. 2.6 Fail-Safe Mode
  6. 3Power Electronics
    1. 3.1 VSUP
    2. 3.2 VHSS
    3. 3.3 VCAN
    4. 3.4 VCC1
    5. 3.5 VCC2
    6. 3.6 VEXMON, VEXCTRL, and VEXCC
    7. 3.7 HSSx
  7. 4Communication Capabilities
    1. 4.1 CAN-FD and Classical CAN
    2. 4.2 CAN-SIC
    3. 4.3 LIN
  8. 5Protection Features
    1. 5.1 Undervoltage (UV) Monitors
      1. 5.1.1 VSUP
      2. 5.1.2 VHSS
      3. 5.1.3 VCAN
      4. 5.1.4 VEXCC
      5. 5.1.5 VCC1
      6. 5.1.6 VCC2
    2. 5.2 Overvoltage (OV) Monitors
      1. 5.2.1 HSSx
      2. 5.2.2 VCC1
      3. 5.2.3 VCC2
      4. 5.2.4 VEXCC
    3. 5.3 Short Circuit (SC) Monitors
      1. 5.3.1 VCC1
      2. 5.3.2 VCC2
      3. 5.3.3 VEXCC
    4. 5.4 Electrical Faults and Impact on SBC Mode
    5. 5.5 Temperature Sensors
    6. 5.6 Watchdog
      1. 5.6.1 Watchdog Error Counter
      2. 5.6.2 Timeout
      3. 5.6.3 Window
      4. 5.6.4 Initial Long Window
      5. 5.6.5 Q&A
    7. 5.7 Communication Fault Monitoring
      1. 5.7.1 CAN
      2. 5.7.2 LIN
    8. 5.8 LIMP
  9. 6Programming, Memory, and Control
    1. 6.1 SPI
    2. 6.2 EEPROM
    3. 6.3 Interrupts
    4. 6.4 Control
  10. 7Miscellaneous Features
    1. 7.1 Local Wake Ups
    2. 7.2 CAN Bus Wake Up (BWRR)
    3. 7.3 Partial Networking
    4. 7.4 GFO, nRST, and SW
  11. 8Summary
  12. 9References

5.5 Temperature Sensors

There are two separate temperature sensors monitoring the dies temperature on devices within the TCAN28XX family. The first sensor covers VCC1 LDO, external PNP control pins, and VEXCC; while the second covers VCC2 LDO, CAN transceiver, and LIN transceiver (if device is LIN capable). An overview of thermal specifications is shown in the following table.

Table 5-3 Thermal Shutdown (TSD) Key Specifications
Spec. ID Spec. Description Min Typical Max
TSDWR Thermal Shutdown Warning 145°C - 165°C
TSDWF Thermal Shutdown Warning Release 130°C - 155°C
TSDR Thermal Shutdown 165°C - 200°C
TSDF Thermal Shutdown Release 155°C - 190°C

The first temperature sensor that covers VCC1 as well as VEXCC and the associated control pins includes a thermal shutdown warning TSDW that can set an interrupt if crossed. The warning doesn’t impact how the device is operating, but acts as an alert of a possible thermal shutdown occurring soon if action is not taken. If VCC1 or VEXCC see an increase in temperature to the thermal shutdown level, TSD, the TSD interrupt flag for VCC1/VEXCC can be set. VCC1 and VEXCC can be shut off during a thermal shutdown and the SBC can enter fail-safe mode if enabled and sleep otherwise and the nRST pin can be pulled low. If the device has fail-safe mode enabled if the die temperature falls below TSDF for 1s the device can transition to restart mode and turn VCC1 and VEXCC (if utilized) back on. During the thermal shutdown event VCC1 is off and the high side switches configuration can be reset – so if cyclic sensing is being utilized when a TSD event occurs the cyclic sensing functionality is no longer present.

The second temperature sensor covers VCC2 as well as the integrated transceivers. If a TSD event occurs on the second sensor VCC2 is shut off with the status being changed to 0 while the transceivers can be put into listen mode; this can also be marked with an interrupt being generated. Once the temperature has dropped below TSDF the transceivers can be re-enabled and after 1s VCC2 can be turned back on. If VCC2 is being used to power VCAN during a TSD event where VCC2 is shutoff a UVCAN event can occur putting the CAN transceiver into a wake capable state and cannot be re-enabled until VCC2 is fully powered again.