SLLSFE8B November   2024  – November 2025 TCAN2845-Q1 , TCAN2847-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
            1. 8.3.11.1.1.1 Interaction Between WAKE1_SENSE/OV_WAKE12SW_DIS and HSS4 Function in Normal Mode
          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 ( TCAN2847x-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
              1. 8.4.8.9.2.1.1 Watchdog Configuration in SPI Two-byte Mode
          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 Registers
    1. 9.1 Registers
      1. 9.1.1  DEVICE_ID_y Register (Address = 00h + formula) [reset = xxh]
      2. 9.1.2  REV_ID Register (Address = 08h) [reset = 2Xh]
      3. 9.1.3  SPI_CONFIG Register (Address = 09h) [reset = 00h]
      4. 9.1.4  CRC_CNTL Register (Address = 0Ah) [reset = 00h]
      5. 9.1.5  CRC_POLY_SET (Address = 0Bh) [reset = 00h]
      6. 9.1.6  SBC_CONFIG (Address = 0Ch) [reset = 06h]
      7. 9.1.7  VREG_CONFIG1 (Address = 0Dh) [reset = 80h]
      8. 9.1.8  SBC_CONFIG1 Register (Address = 0Eh) [reset = 01h]
      9. 9.1.9  Scratch_Pad_SPI Register (Address = 0Fh) [reset = 00h]
      10. 9.1.10 CAN_CNTRL_1 Register (Address = 10h) [reset = 04h]
      11. 9.1.11 WAKE_PIN_CONFIG1 Register (Address = 11h) [reset = 00h]
      12. 9.1.12 WAKE_PIN_CONFIG2 Register (Address = 12h) [reset = 02h]
      13. 9.1.13 WD_CONFIG_1 Register (Address = 13h) [reset = 82h]
      14. 9.1.14 WD_CONFIG_2 Register (Address = 14h) [reset = 60h]
      15. 9.1.15 WD_INPUT_TRIG Register (Address = 15h) [reset = 00h]
      16. 9.1.16 WD_RST_PULSE Register (Address = 16h) [reset = 00h]
      17. 9.1.17 FSM_CONFIG Register (Address = 17h) [reset = 00h]
      18. 9.1.18 FSM_CNTR Register (Address = 18h) [reset = 00h]
      19. 9.1.19 DEVICE_CONFIG0 Register (Address = 19h) [reset = 10h]
      20. 9.1.20 DEVICE_CONFIG1 (Address = 1Ah) [reset = 00h]
      21. 9.1.21 DEVICE_CONFIG2 (Address = 1Bh) [reset = 00h]
      22. 9.1.22 SWE_TIMER (Address = 1Ch) [reset = 28h]
      23. 9.1.23 LIN_CNTL (Address = 1Dh) [reset = 20h]
      24. 9.1.24 HSS_CNTL (Address = 1Eh) [reset = 00h]
      25. 9.1.25 PWM1_CNTL1 (Address = 1Fh) [reset = 00h]
      26. 9.1.26 PWM1_CNTL2 (Address = 20h) [reset = 00h]
      27. 9.1.27 PWM1_CNTL3 (Address = 21h) [reset = 00h]
      28. 9.1.28 PWM2_CNTL1 (Address = 22h) [reset = 00h]
      29. 9.1.29 PWM2_CNTL2 (Address = 23h) [reset = 00h]
      30. 9.1.30 PWM2_CNTL3 (Address = 24h) [reset = 00h]
      31. 9.1.31 TIMER1_CONFIG (Address = 25h) [reset = 00h]
      32. 9.1.32 TIMER2_CONFIG (Address = 26h) [reset = 00h]
      33. 9.1.33 RSRT_CNTR (Address = 28h) [reset = 40h]
      34. 9.1.34 nRST_CNTL (Address = 29h) [reset = 2Ch]
      35. 9.1.35 WAKE_PIN_CONFIG3 Register (Address = 2Ah) [reset = E0h]
      36. 9.1.36 WAKE_PIN_CONFIG4 Register (Address = 2Bh) [reset = 22h]
      37. 9.1.37 WD_QA_CONFIG Register (Address = 2Dh) [reset = 0Ah]
      38. 9.1.38 WD_QA_ANSWER Register (Address = 2Eh) [reset = 00h]
      39. 9.1.39 WD_QA_QUESTION Register (Address = 2Fh) [reset = 3Ch]
      40. 9.1.40 SW_ID1 Register (Address = 30h) [reset = 00h]
      41. 9.1.41 SW_ID2 Register (Address = 31h) [reset = 00h]
      42. 9.1.42 SW_ID3 Register (Address = 32h) [reset = 00h]
      43. 9.1.43 SW_ID4 Register (Address = 33h) [reset = 00h]
      44. 9.1.44 SW_ID_MASK1 Register (Address = 34h) [reset = 00h]
      45. 9.1.45 SW_ID_MASK2 Register (Address = 35h) [reset = 00h]
      46. 9.1.46 SW_ID_MASK3 Register (Address = 36h) [reset = 00h]
      47. 9.1.47 SW_ID_MASK4 Register (Address = 37h) [reset = 00h]
      48. 9.1.48 SW_ID_MASK_DLC Register (Address = 38h) [reset = 00h]
      49. 9.1.49 DATA_y Register (Address = 39h + formula) [reset = 00h]
      50. 9.1.50 SW_RSVD_y Register (Address = 41h + formula) [reset = 00h]
      51. 9.1.51 SW_CONFIG_1 Register (Address = 44h) [reset = 50h]
      52. 9.1.52 SW_CONFIG_2 Register (Address = 45h) [reset = 00h]
      53. 9.1.53 SW_CONFIG_3 Register (Address = 46h) [reset = 1Fh]
      54. 9.1.54 SW_CONFIG_4 Register (Address = 47h) [reset = 00h]
      55. 9.1.55 SW_CONFIG_RSVD_y Register (Address = 48h + formula) [reset = 00h]
      56. 9.1.56 HSS_CNTL2 (Address = 4Dh) [reset = 00h]
      57. 9.1.57 EEPROM_CONFIG (Address = 4Eh) [reset = 00h]
      58. 9.1.58 HSS_CNTL3 (Address = 4Fh) [reset = 00h]
      59. 9.1.59 INT_GLOBAL Register (Address = 50h) [reset = 00h]
      60. 9.1.60 INT_1 Register (Address = 51h) [reset = 00h]
      61. 9.1.61 INT_2 Register (Address = 52h) [reset = 40h]
      62. 9.1.62 INT_3 Register (Address 53h) [reset = 00h]
      63. 9.1.63 INT_CANBUS_1 Register (Address = 54h) [reset = 00h]
      64. 9.1.64 INT_7 (Address = 55h) [reset = 00h]
      65. 9.1.65 INT_EN_1 Register (Address = 56h) [reset = FFh]
      66. 9.1.66 INT_EN_2 Register (Address = 57h) [reset = 7Eh]
      67. 9.1.67 INT_EN_3 Register (Address = 58h) [reset = FEh]
      68. 9.1.68 INT_EN_CANBUS_1 Register (Address = 59h) [reset = BFh]
      69. 9.1.69 INT_4 Register (Address = 5Ah) [reset = 00h]
      70. 9.1.70 INT_6 Register (Address 5Ch) [reset = 00h]
      71. 9.1.71 INT_EN_4 Register (Address = 5Eh) [reset = DFh]
      72. 9.1.72 INT_EN_6 Register (Address = 60h) [reset = FFh]
      73. 9.1.73 INT_EN_7 Register (Address = 62) [reset = FFh]
  11. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 CAN BUS Loading, Length and Number of Nodes
      2. 10.1.2 CAN Termination
        1. 10.1.2.1 Termination
      3. 10.1.3 Channel Expansion
        1. 10.1.3.1 Channel Expansion for LIN
        2. 10.1.3.2 Channel Expansion for CAN FD
      4. 10.1.4 Device Brownout information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
        1. 10.2.1.1 LTXD Dominant State Timeout Application Note
      2. 10.2.2 Detailed Design Procedures
        1. 10.2.2.1 CAN Detailed Design Procedure
        2. 10.2.2.2 LIN Detailed Design Procedures
      3. 10.2.3 Application Curves
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  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
8.4.8.9.4.3 WD Question and Answer Value Generation

The 4-bit WD question, WD_QA_QUESTION[3:0], is generated by 4-bit Markov chain process. A Markov chain is a stochastic process with Markov property, which means that state changes are probabilistic, and the future state depends only on the current state. The valid and complete WD answer sequence for each WD Q&A mode is as follows:

  • WD Q&A mode expectations:
    1. Three correct SPI WD answers are received during RESPONSE WINDOW 1.
    2. One correct SPI WD answer is received during RESPONSE WINDOW 2.
    3. In addition to the previously listed timing, the sequence of four responses shall be correct.

The WD question value is latched in the WD_QUESTION bits of the WD_QA_QUESTION register and can be read out at any time.

The Markov chain process is clocked by the 4-bit Question counter at the transition from 1111b to 0000b. This includes the condition of a correct answer (correct answer value and correct timing response). The logic combination of the 4-bit questions WD_QA_QUESTION [3:0] generation is given in Figure 8-64. The question counter is reset to default value of 0000b and the Markov chain is re-initialized to programmed register value when a watchdog fail puts the device in restart mode.

TCAN2845-Q1 TCAN2847-Q1 Watchdog Question Generation
A.
  • Register 8'h2D[3:0] WD_QA_POLY_SEED maps as bit 3 = X1, bit 2 = X2. bit 1 = X3 and bit 0 = X4.
  • If the current y value is 0000, the next y value is 0001. The next watchdog question generation process starts from that value. Any changes to WD_QA_CONFIG register in Standby mode re-initializes the Markov chain to the current register value. The question counter is not affected.
Figure 8-64 Watchdog Question Generation