SLLSFM2A November   2024  – October 2025 TCAN2855-Q1 , TCAN2857-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  IEC ESD Ratings
    4. 6.4  Recommended Operating Conditions
    5. 6.5  Thermal Information
    6. 6.6  Supply Characteristics
    7. 6.7  Electrical Characteristics
    8. 6.8  Timing Requirements
    9. 6.9  Switching Characteristics
    10. 6.10 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  VSUP Pin
      2. 8.3.2  VCC1 Regulator
      3. 8.3.3  VCC2 Regulator
        1. 8.3.3.1 VCC2 Short to Battery Protection
      4. 8.3.4  nRST Pin
      5. 8.3.5  VEXCC Regulator
      6. 8.3.6  CAN FD Transceiver
        1. 8.3.6.1 Driver and Receiver Function
        2. 8.3.6.2 CAN Bus Biasing
      7. 8.3.7  LIN Transceiver
        1. 8.3.7.1 LIN Transmitter Characteristics
        2. 8.3.7.2 LIN Receiver Characteristics
        3. 8.3.7.3 LIN Termination
      8. 8.3.8  GND
      9. 8.3.9  LIMP Pin
      10. 8.3.10 High-side Switches (HSS1- HSS4)
      11. 8.3.11 WAKE1, WAKE2 and WAKE3/DIR Pins
        1. 8.3.11.1 WAKE Pins Alternate Configurations
          1. 8.3.11.1.1 VBAT monitoring
          2. 8.3.11.1.2 Direct Drive
      12. 8.3.12 SDO Pin
      13. 8.3.13 nCS Pin
      14. 8.3.14 SCK Pin
      15. 8.3.15 SDI Pin
      16. 8.3.16 Interrupt Function (nINT)
      17. 8.3.17 SW Pin
      18. 8.3.18 GFO Pin
    4. 8.4 Device Functional Modes
      1. 8.4.1 Init Mode
      2. 8.4.2 Normal Mode
      3. 8.4.3 Standby Mode
      4. 8.4.4 Restart Mode
      5. 8.4.5 Fail-safe Mode
        1. 8.4.5.1 SBC Faults
        2. 8.4.5.2 CAN Transceiver Faults
        3. 8.4.5.3 LIN Transceiver Faults ( TCAN2857-Q1)
      6. 8.4.6 Sleep Mode
      7. 8.4.7 Wake Functions
        1. 8.4.7.1 CAN Bus Wake Using CRXD Request (BWRR) in Sleep Mode
        2. 8.4.7.2 LIN Bus Wake
        3. 8.4.7.3 Local Wake Up (LWU) via WAKEx Input Terminal
          1. 8.4.7.3.1 Static Wake
          2. 8.4.7.3.2 Cyclic Sensing Wake
        4. 8.4.7.4 Cyclic Wake
        5. 8.4.7.5 Direct Drive in Sleep Mode
        6. 8.4.7.6 Selective Wake-up
          1. 8.4.7.6.1 Selective Wake Mode
          2. 8.4.7.6.2 Frame Detection
          3. 8.4.7.6.3 Wake-Up Frame (WUF) Validation
          4. 8.4.7.6.4 WUF ID Validation
          5. 8.4.7.6.5 WUF DLC Validation
          6. 8.4.7.6.6 WUF Data Validation
          7. 8.4.7.6.7 Frame Error Counter
          8. 8.4.7.6.8 CAN FD Frame Tolerance
          9. 8.4.7.6.9 8Mbps Filtering
      8. 8.4.8 Protection Features
        1. 8.4.8.1  Fail-safe Features
          1. 8.4.8.1.1 Sleep Mode Using Sleep Wake Error
        2. 8.4.8.2  Device Reset
        3. 8.4.8.3  Floating Terminals
        4. 8.4.8.4  TXD Dominant Time Out (DTO)
        5. 8.4.8.5  LIN Bus Stuck Dominant System Fault: False Wake Up Lockout
        6. 8.4.8.6  CAN Bus Short Circuit Current Limiting
        7. 8.4.8.7  Thermal Shutdown
        8. 8.4.8.8  Under and Over Voltage Lockout and Unpowered Device
          1. 8.4.8.8.1 Under-voltage
            1. 8.4.8.8.1.1 VSUP and VHSS Under-voltage
            2. 8.4.8.8.1.2 VCC1 Under-voltage
            3. 8.4.8.8.1.3 VCC2 and VEXCC Under-voltage
            4. 8.4.8.8.1.4 VCAN Under-voltage
          2. 8.4.8.8.2 VCC1, VCC2 and VEXCC Over-voltage
          3. 8.4.8.8.3 VCC1, VCC2 and VEXCC Short Circuit
        9. 8.4.8.9  Watchdog
          1. 8.4.8.9.1 Watchdog Error Counter and Action
          2. 8.4.8.9.2 Watchdog SPI Programming
            1. 8.4.8.9.2.1 Watchdog Configuration Registers Lock and Unlock
          3. 8.4.8.9.3 Watchdog Timing
          4. 8.4.8.9.4 Question and Answer Watchdog
            1. 8.4.8.9.4.1 WD Question and Answer Basic Information
            2. 8.4.8.9.4.2 Question and Answer Register and Settings
            3. 8.4.8.9.4.3 WD Question and Answer Value Generation
              1. 8.4.8.9.4.3.1 Answer Comparison
              2. 8.4.8.9.4.3.2 Sequence of the 2-bit Watchdog Answer Counter
            4. 8.4.8.9.4.4 Question and Answer WD Example
              1. 8.4.8.9.4.4.1 Example Configuration for Desired Behavior
              2. 8.4.8.9.4.4.2 Example of Performing a Question and Answer Sequence
        10. 8.4.8.10 Bus Fault Detection and Communication
    5. 8.5 Programming
      1. 8.5.1 SPI Communication
        1. 8.5.1.1 Cyclic Redundancy Check
        2. 8.5.1.2 Chip Select Not (nCS):
        3. 8.5.1.3 SPI Clock Input (SCK):
        4. 8.5.1.4 SPI Data Input (SDI):
        5. 8.5.1.5 SPI Data Output (SDO):
      2. 8.5.2 EEPROM
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 CAN BUS Loading, Length and Number of Nodes
      2. 9.1.2 CAN Termination
        1. 9.1.2.1 Termination
      3. 9.1.3 Channel Expansion
        1. 9.1.3.1 Channel Expansion for LIN
        2. 9.1.3.2 Channel Expansion for CAN FD
      4. 9.1.4 Device Brownout information
      5. 9.1.5 Typical Application
        1. 9.1.5.1 Design Requirements
          1. 9.1.5.1.1 LTXD Dominant State Timeout Application Note
        2. 9.1.5.2 Detailed Design Procedures
          1. 9.1.5.2.1 CAN Detailed Design Procedure
          2. 9.1.5.2.2 LIN Detailed Design Procedures
        3. 9.1.5.3 Application Curves
    2. 9.2 Power Supply Recommendations
    3. 9.3 Layout
      1. 9.3.1 Layout Guidelines
      2. 9.3.2 Layout Example
  11. 10Registers
    1. 10.1 Registers
      1. 10.1.1  DEVICE_ID_y Register (Address = 00h + formula) [reset = xxh]
      2. 10.1.2  REV_ID Register (Address = 08h) [reset = 2Xh]
      3. 10.1.3  SPI_CONFIG Register (Address = 09h) [reset = 00h]
      4. 10.1.4  CRC_CNTL Register (Address = 0Ah) [reset = 00h]
      5. 10.1.5  CRC_POLY_SET (Address = 0Bh) [reset = 00h]
      6. 10.1.6  SBC_CONFIG (Address = 0Ch) [reset = 06h]
      7. 10.1.7  VREG_CONFIG1 (Address = 0Dh) [reset = 80h]
      8. 10.1.8  SBC_CONFIG1 Register (Address = 0Eh) [reset = 01h]
      9. 10.1.9  Scratch_Pad_SPI Register (Address = 0Fh) [reset = 00h]
      10. 10.1.10 CAN_CNTRL_1 Register (Address = 10h) [reset = 04h]
      11. 10.1.11 WAKE_PIN_CONFIG1 Register (Address = 11h) [reset = 00h]
      12. 10.1.12 WAKE_PIN_CONFIG2 Register (Address = 12h) [reset = 02h]
      13. 10.1.13 WD_CONFIG_1 Register (Address = 13h) [reset = 82h]
      14. 10.1.14 WD_CONFIG_2 Register (Address = 14h) [reset = 60h]
      15. 10.1.15 WD_INPUT_TRIG Register (Address = 15h) [reset = 00h]
      16. 10.1.16 WD_RST_PULSE Register (Address = 16h) [reset = 00h]
      17. 10.1.17 FSM_CONFIG Register (Address = 17h) [reset = 00h]
      18. 10.1.18 FSM_CNTR Register (Address = 18h) [reset = 00h]
      19. 10.1.19 DEVICE_CONFIG0 Register (Address = 19h) [reset = 10h]
      20. 10.1.20 DEVICE_CONFIG1 (Address = 1Ah) [reset = 00h]
      21. 10.1.21 DEVICE_CONFIG2 (Address = 1Bh) [reset = 00h]
      22. 10.1.22 SWE_TIMER (Address = 1Ch) [reset = 28h]
      23. 10.1.23 LIN_CNTL (Address = 1Dh) [reset = 20h]
      24. 10.1.24 HSS_CNTL (Address = 1Eh) [reset = 00h]
      25. 10.1.25 PWM1_CNTL1 (Address = 1Fh) [reset = 00h]
      26. 10.1.26 PWM1_CNTL2 (Address = 20h) [reset = 00h]
      27. 10.1.27 PWM1_CNTL3 (Address = 21h) [reset = 00h]
      28. 10.1.28 PWM2_CNTL1 (Address = 22h) [reset = 00h]
      29. 10.1.29 PWM2_CNTL2 (Address = 23h) [reset = 00h]
      30. 10.1.30 PWM2_CNTL3 (Address = 24h) [reset = 00h]
      31. 10.1.31 TIMER1_CONFIG (Address = 25h) [reset = 00h]
      32. 10.1.32 TIMER2_CONFIG (Address = 26h) [reset = 00h]
      33. 10.1.33 RSRT_CNTR (Address = 28h) [reset = 40h]
      34. 10.1.34 nRST_CNTL (Address = 29h) [reset = 2Ch]
      35. 10.1.35 WAKE_PIN_CONFIG3 Register (Address = 2Ah) [reset = E0h]
      36. 10.1.36 WAKE_PIN_CONFIG4 Register (Address = 2Bh) [reset = 22h]
      37. 10.1.37 WD_QA_CONFIG Register (Address = 2Dh) [reset = 0Ah]
      38. 10.1.38 WD_QA_ANSWER Register (Address = 2Eh) [reset = 00h]
      39. 10.1.39 WD_QA_QUESTION Register (Address = 2Fh) [reset = 3Ch]
      40. 10.1.40 SW_ID1 Register (Address = 30h) [reset = 00h]
      41. 10.1.41 SW_ID2 Register (Address = 31h) [reset = 00h]
      42. 10.1.42 SW_ID3 Register (Address = 32h) [reset = 00h]
      43. 10.1.43 SW_ID4 Register (Address = 33h) [reset = 00h]
      44. 10.1.44 SW_ID_MASK1 Register (Address = 34h) [reset = 00h]
      45. 10.1.45 SW_ID_MASK2 Register (Address = 35h) [reset = 00h]
      46. 10.1.46 SW_ID_MASK3 Register (Address = 36h) [reset = 00h]
      47. 10.1.47 SW_ID_MASK4 Register (Address = 37h) [reset = 00h]
      48. 10.1.48 SW_ID_MASK_DLC Register (Address = 38h) [reset = 00h]
      49. 10.1.49 DATA_y Register (Address = 39h + formula) [reset = 00h]
      50. 10.1.50 SW_RSVD_y Register (Address = 41h + formula) [reset = 00h]
      51. 10.1.51 SW_CONFIG_1 Register (Address = 44h) [reset = 50h]
      52. 10.1.52 SW_CONFIG_2 Register (Address = 45h) [reset = 00h]
      53. 10.1.53 SW_CONFIG_3 Register (Address = 46h) [reset = 1Fh]
      54. 10.1.54 SW_CONFIG_4 Register (Address = 47h) [reset = 00h]
      55. 10.1.55 SW_CONFIG_RSVD_y Register (Address = 48h + formula) [reset = 00h]
      56. 10.1.56 HSS_CNTL2 (Address = 4Dh) [reset = 00h]
      57. 10.1.57 EEPROM_CONFIG (Address = 4Eh) [reset = 00h]
      58. 10.1.58 HSS_CNTL3 (Address = 4Fh) [reset = 00h]
      59. 10.1.59 INT_GLOBAL Register (Address = 50h) [reset = 00h]
      60. 10.1.60 INT_1 Register (Address = 51h) [reset = 00h]
      61. 10.1.61 INT_2 Register (Address = 52h) [reset = 40h]
      62. 10.1.62 INT_3 Register (Address 53h) [reset = 00h]
      63. 10.1.63 INT_CANBUS_1 Register (Address = 54h) [reset = 00h]
      64. 10.1.64 INT_7 (Address = 55h) [reset = 00h]
      65. 10.1.65 INT_EN_1 Register (Address = 56h) [reset = FFh]
      66. 10.1.66 INT_EN_2 Register (Address = 57h) [reset = 7Eh]
      67. 10.1.67 INT_EN_3 Register (Address = 58h) [reset = FEh]
      68. 10.1.68 INT_EN_CANBUS_1 Register (Address = 59h) [reset = BFh]
      69. 10.1.69 INT_4 Register (Address = 5Ah) [reset = 00h]
      70. 10.1.70 INT_6 Register (Address 5Ch) [reset = 00h]
      71. 10.1.71 INT_EN_4 Register (Address = 5Eh) [reset = DFh]
      72. 10.1.72 INT_EN_6 Register (Address = 60h) [reset = FFh]
      73. 10.1.73 INT_EN_7 Register (Address = 62) [reset = FFh]
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 CAN Transceiver Physical Layer Standards:
      2. 11.1.2 LIN Transceiver Physical Layer Standards
      3. 11.1.3 EMC Requirements:
      4. 11.1.4 Conformance Test Requirements:
      5. 11.1.5 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Mechanical Data

8.4.5 Fail-safe Mode

The device has a fail-safe mode, default on, which is entered when certain fault events take place. When fail-safe mode is entered, a global interrupt is issued and the sleep wake error (SWE) timer, tINACTIVE, if enabled starts and VCC1, VCC2 and VEXCC are turned off. The reason for entering fail-safe mode is provided by register 8'h17[3:1] and expanded further with other interrupt flags. This mode can be disabled by using register 8'h17[0], but the recommendation is to stay enabled as fault monitoring is active in fail-safe mode and not sleep mode. This mode turns on LIMP and brings other functions into lower power mode states. When entering fail-safe mode the LDOs are kept off for at least tLDOOFF, approximately 300ms. During this time wake events are monitored and preserved. After tLDOOFF times out wake events causes the device to transition to restart mode. If enabled and the SWE timer times out prior to faults being cleared and a wake event taking place, the device transitions to sleep mode. Figure 8-26 shows the various fault conditions that causes the device to enter fail-safe mode. If the fault conditions are cleared and a wake event takes place, the device transitions to restart mode. Figure 8-27 provides a high level flow chart for fail-safe mode.

A fail-safe mode counter is available allowing a set number of fail-safe events in a row which then causes the device to perform the programmed action which can include going to sleep where a WUP, WUF or LWU event does not wake the device. A power on reset is required. The counter is default disabled and can be enabled at 8'h17[7:4] ≠ 0000b. The counter expiration action is at 8'h17[7:4]. The number of events before action is programmed is set at 8'h18[7:4] with a value up to 16 events. 8'h18[3:0] is the running up/down fail-safe event counter that can be read and cleared.

There are multiple ways to exit fail-safe mode depending upon the fault and programmed configuration.

  • By default, the SWE timer is disabled. When enabled these are the transition paths out of fail-safe mode.
    • A wake event and cleared fault sends the device into restart mode.
    • If enabled, the SWE timer timing out causes the device to transition to sleep mode, and VCC1 remains off even if VCC1_CFG = 01b is on.
    • If FSM_CYC_WK_EN, 8'h1A[0] = 1b, the device wakes up during the on time of the selected timer and check to see if the fault has cleared. If so, the device transitions to restart mode.

TCAN2855-Q1 TCAN2857-Q1 Fail-safe ModeFigure 8-26 Fail-safe Mode
TCAN2855-Q1 TCAN2857-Q1 Fail-safe mode flow chartFigure 8-27 Fail-safe mode flow chart
Note:

For the device to enter fail-safe mode, there has to be a method for the device to wake up. This can be by the communication bus or a WAKE pin. If these are all disabled for fail-safe mode, the device automatically makes the CAN FD and LIN transceivers wake capable.

When the device enters fail-safe mode, the SWE timer automatically starts, if enabled.

  • If SWE timer times out the device enters sleep mode
  • If a wake event takes place prior to the SWE timer timing out, the device determines if fault is still present.
    • If fault is present the device stays in fail-safe mode monitoring the fault.
    • If fault has cleared the device enters restart mode.

When fail-safe mode is entered due to any condition other than TSD the following takes place.

  • The VCC1 LDO is turned off. If the fault impacts load sharing; both are turned off. If the device receives a wake event, the LDO is turned on for tLDOON to determine if the short circuit event is still present.
    • At the end of tLDOON, if a short circuit is detected the device turns off the LDO and wait for next wake event.
  • Over-voltage is continuously monitored immediately enters sleep mode.
  • If fault is cleared the device enters restart mode.