SLLU342 May   2022 TCAN1462-Q1

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Overview
    2. 1.2 CAN EVM
      1.      5
      2.      6
      3. 1.2.1 Bill of Materials
  3. 2EVM Setup and Operation
    1. 2.1 Overview and Basic Operation Settings
      1. 2.1.1  VCC Power Supply (J2, J3, J9, and TP10)
      2. 2.1.2  I/O Power Supply VIO (J2, J10, and TP8)
      3. 2.1.3  Main Supply and I/O Header (J2)
      4. 2.1.4  TXD Input (J2 or TP6)
      5. 2.1.5  RXD Output (J2 or TP7)
      6. 2.1.6  STB or Pin 8 (J1, J2, or TP1)
      7. 2.1.7  J1 Configuration
      8. 2.1.8  TP1 Configuration
      9. 2.1.9  VIO or Pin 5 (J2, J10, or TP8)
      10. 2.1.10 J10 Configurations
      11. 2.1.11 J2 Configuration
      12. 2.1.12 SIC Network Configuration (J7 & J8)
    2. 2.2 Using CAN Bus Load, Termination, and Protection Configurations
    3. 2.3 Using Customer Installable I/O Options for Current Limiting, Pullup and Pulldown, Noise Filtering
  4. 3CAN EVM Configuration for TCAN1462-Q1 (Factory Installed)

2.2 Using CAN Bus Load, Termination, and Protection Configurations

The CAN EVM is populated with two 120-Ω power resistors selectable via jumpers between CANH and CANL. When using one resistor, the EVM is used as a terminated end of a bus. For electrical measurements to represent the total loading of the bus, use both 120-Ω resistors in parallel to give the standard 60-Ω load for parametric measurement. The EVM also has footprints for split termination if needed for the application. Table 2-2 summarizes how to use these termination options. If using split termination, match the resistors. Calculate the common mode filter frequency using: fC = 1 / (2πRC). Normally, the split capacitance is in the range of 4.7 nF to 100 nF. Note the that a common-mode filter frequency, not a differential filter impacts the differential CAN signal directly.

Table 2-2 Bus Termination Configuration
Termination Configuration120-Ω ResistorsSplit Termination FootprintsSplit Termination Footprints
J5J6R4R10C4
Standard termination (120 Ω)shortedopenN/AN/AN/A
60-Ω load - electrical parametricsshortedshorted
Split termination (common mode stabilization)openopen60 Ω60 Ωpopulated

The EVM also has footprints for various protection schemes to enhance robustness for extreme system-level EMC/ESD requirements. Table 2-3 summarizes these options.

Table 2-3 Protection and Filtering Configuration
Configuration Footprint Reference Use Case Population and Description
Series resistors or common mode choke R5/R9 or L1 (common footprint) Direct CAN transceiver to bus connection R5 and R9 populated with 0 Ω (default population)
Series resistance protection, CAN transceiver to bus connection R5 and R9 populated with MELF resistor as necessary for harsh EMC environment
CM choke (bus filter) L1 populated with CM choke to filter noise as necessary for harsh EMC environment
Bus filtering caps and transient protection C2/C6 Bus filter Filter noise as necessary for harsh EMC environment. Use filter caps in combination with L1 CM choke.
D1 Transient and ESD protection To add extra protection for system level transients and ±30 kV ESD events, ESD2CAN24-Q1is populated in the D1 socket.