SLLU355 October   2022 TCAN1046A-Q1 , TCAN1046AV-Q1

 

  1.   TCAN1046A/V Evaluation Module
  2.   Trademarks
  3. 1Introduction
    1. 1.1 Overview
    2. 1.2 CAN EVM
      1. 1.2.1 Schematic
      2. 1.2.2 Jumper Connections
  4. 2EVM Setup and Operation
    1. 2.1 Overview and Basic Operation Settings
      1. 2.1.1 VCC Power Supply (J6 and J21)
      2. 2.1.2 I/O Power Supply VIO (J17)
      3. 2.1.3 Transmit and Receive Connections(J11 and J22)
      4. 2.1.4 TXD Inputs (J11/J22, TP13 and TP14/TP29 and TP31)
      5. 2.1.5 RXD Outputs (J11/J22, TP15 and TP16/TP30 and TP34)
      6. 2.1.6 STBY inputs (J12 and J13/J24 and J25, TP10 and TP12/TP32 and TP33)
      7. 2.1.7 Bus Observation (J3 or J8/J14 or J19)
      8. 2.1.8 Bus protection
    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
  5. 3CAN EVM Configuration for TCAN1046A and TCAN1046AV

Using CAN Bus Load, Termination, and Protection Configurations

The TCAN1046AEVM has several bus termination options for all available buses. For the TCAN1046A half of the board (top half), the termination on the CAN bus (CANH and CANL) can be configured with the J4 and J5 (CAN1) or J7 and J9 (CAN2) jumpers. For the TCAN1046AV half of the board (bottom half), the termination on the CAN bus (CANH and CANL) can be configured with the J15 and J16 (CAN1) or J18 and J20 (CAN2) jumpers. Each jumper adds 120-Ω termination to the respective bus. 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 footprint for split termination is also available and can be populated on all 4 buses. These components are not populated out of the box. Table 2-3 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. Keep in mind this is the common-mode filter frequency, not a differential filter that impacts the differential CAN signal directly.

Table 2-3 TCAN1046A Bus Termination Configuration
Termination Configuration120-Ω Resistors (CAN1)120-Ω Resistors (CAN2)Split Termination Footprints (CAN1)Split Termination Footprints (CAN2)Split Termination Footprints (CAN1)Split Termination Footprints (CAN2)
J5J9J4J7R2R6R15R11C2C9
Standard termination (120 Ω)shortedopenN/AN/AN/A
60-Ω load - electrical parametericsshortedshorted
Split termination (common mode stabilization)openopen60 Ω60 Ωpopulated
Table 2-4 TCAN1046AV Bus Termination Configuration
Termination Configuration120-Ω Resistors (CAN1)120-Ω Resistors (CAN2)Split Termination Footprints (CAN1)Split Termination Footprints (CAN2)Split Termination Footprints (CAN1)Split Termination Footprints (CAN2)
J16J20J15J18R31R36R40R44C16C23
Standard termination (120 Ω)shortedopenN/AN/AN/A
60-Ω load - electrical parametericsshortedshorted
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 requirements. Table 2-5 summarizes these options.

Table 2-5 TCAN1046A Protection and Filtering Configuration
ConfigurationFootprint ReferenceUse CasePopulation and Description
Series resistors or common mode chokeR1/R9 or L1 (common footprint)Direct CAN1 transceiver to bus connectionR1 and R9 populated with 0 Ω
Series resistance protection, CAN1 transceiver to bus connectionR1and R9 populated with MELF resistor as necessary for harsh EMC environment
CM choke (CAN1 bus filter)L1 populated with CM choke to filter noise as necessary for harsh EMC environment (default population)
R10/R17 or L2 (common footprint)Direct CAN2 transceiver to bus connectionR10 and R17 populated with 0 Ω
Series resistance protection, CAN2 transceiver to bus connectionR10 and R17 populated with MELF resistor as necessary for harsh EMC environment
CM choke (CAN2 bus filter)L2 populated with CM choke to filter noise as necessary for harsh EMC environment (default population)
Bus filtering caps transient protectionC1/C3Bus filterFilter noise as necessary for harsh EMC environment. Use filter caps in combination with L1 CM choke.
C8/C10Filter noise as necessary for harsh EMC environment. Use filter caps in combination with L2 CM choke.
C1/C3 or D1Transient and ESD protectionTo add extra protection for system level transients and ESD protection, TVS diode population option via D1 footprint or varistor population via C1/C3 footprint.
C8/C10 or D3To add extra protection for system level transients and ESD protection, TVS diode population option via D3 footprint or varistor population via C8/C10 footprint.
Table 2-6 TCAN1046AV Protection and Filtering Configuration
ConfigurationFootprint ReferenceUse CasePopulation and Description
Series resistors or common mode chokeR30/R38 or L3 (common footprint)Direct CAN1 transceiver to bus connectionR30 and R38 populated with 0 Ω
Series resistance protection, CAN1 transceiver to bus connectionR30and R38 populated with MELF resistor as necessary for harsh EMC environment
CM choke (CAN1 bus filter)L3 populated with CM choke to filter noise as necessary for harsh EMC environment (default population)
R39/R46 or L4 (common footprint)Direct CAN2 transceiver to bus connectionR39 and R46 populated with 0 Ω
Series resistance protection, CAN2 transceiver to bus connectionR39 and R46 populated with MELF resistor as necessary for harsh EMC environment
CM choke (CAN2 bus filter)L4 populated with CM choke to filter noise as necessary for harsh EMC environment (default population)
Bus filtering caps transient protectionC15/C17Bus filterFilter noise as necessary for harsh EMC environment. Use filter caps in combination with L3 CM choke.
C22/C24Filter noise as necessary for harsh EMC environment. Use filter caps in combination with L4 CM choke.
C15/C17 or D4Transient and ESD protectionTo add extra protection for system level transients and ESD protection, TVS diode population option via D4 footprint or varistor population via C15/C17 footprint.
C22/C24 or D6To add extra protection for system level transients and ESD protection, TVS diode population option via D6 footprint or varistor population via C22/C24 footprint.