SLLSEQ7E December   2015  – December 2019 TCAN330 , TCAN330G , TCAN332 , TCAN332G , TCAN334 , TCAN334G , TCAN337 , TCAN337G

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Block Diagram
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Options
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Switching Characteristics
    7. 8.7 Typical Characteristics
    8. 8.8 Typical Characteristics, TCAN330 Receiver
    9. 8.9 Typical Characteristics, TCAN330 Driver
  9. 9 Parameter Measurement Information
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
      1. 10.3.1 TXD Dominant Timeout (TXD DTO)
      2. 10.3.2 RXD Dominant Timeout (RXD DTO)
      3. 10.3.3 Thermal Shutdown
      4. 10.3.4 Undervoltage Lockout and Unpowered Device
      5. 10.3.5 Fault Pin (TCAN337)
      6. 10.3.6 Floating Pins
      7. 10.3.7 CAN Bus Short Circuit Current Limiting
      8. 10.3.8 ESD Protection
      9. 10.3.9 Digital Inputs and Outputs
    4. 10.4 Device Functional Modes
      1. 10.4.1 CAN Bus States
      2. 10.4.2 Normal Mode
      3. 10.4.3 Silent Mode
      4. 10.4.4 Standby Mode with Wake
      5. 10.4.5 Bus Wake via RXD Request (BWRR) in Standby Mode
      6. 10.4.6 Shutdown Mode
      7. 10.4.7 Driver and Receiver Function Tables
  11. 11Application and Implementation
    1. 11.1 Application Information
      1. 11.1.1 Bus Loading, Length and Number of Nodes
    2. 11.2 Typical Application
      1. 11.2.1 Design Requirements
        1. 11.2.1.1 CAN Termination
      2. 11.2.2 Detailed Design Procedure
      3. 11.2.3 Application Curves
    3. 11.3 System Examples
      1. 11.3.1 ISO11898 Compliance of TCAN33x Family of 3.3-V CAN Transceivers Introduction
      2. 11.3.2 Differential Signal
      3. 11.3.3 Common-Mode Signal and EMC Performance
  12. 12Power Supply Recommendations
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
  14. 14Device and Documentation Support
    1. 14.1 Related Links
    2. 14.2 Support Resources
    3. 14.3 Trademarks
    4. 14.4 Electrostatic Discharge Caution
    5. 14.5 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

11.1.1 Bus Loading, Length and Number of Nodes

The ISO 11898 standard specifies a data rate up to 1 Mbps, maximum CAN bus cable length of 40 m, maximum drop line (stub) length of 0.3 m and a maximum of 30 nodes. However, with careful network design, the system may have longer cables, longer stub lengths, and many more nodes to a bus. Many CAN organizations and standards have scaled the use of CAN for applications outside the original ISO 11898 standard. They have made system level trade-offs for data rate, cable length, and parasitic loading of the bus. Examples of some of these specifications are ARINC825, CANopen, CAN Kingdom, DeviceNet and NMEA200.

A high number of nodes requires a transceiver with high input impedance and wide common mode range such as the TCAN33x CAN family. ISO 11898-2 specifies the driver differential output with a 60-Ω load (two 120- Ω termination resistors in parallel) and the differential output must be greater than 1.5 V. The TCAN33x devices are specified to meet the 1.5-V requirement with a 50-Ω load across a common mode range of –12 V to 12 V through a 330-Ω coupling network. This network represents the bus loading of 120 TCAN33x transceivers based on their minimum differential input resistance of 40 kΩ.

For CAN network design, margin must be given for signal loss across the system and cabling, parasitic loadings, network imbalances, ground offsets and signal integrity, thus a practical maximum number of nodes may be lower. Bus length may also be extended beyond the original ISO 11898 standard of 40 m by careful system design and data rate tradeoffs. For example, CANopen network design guidelines allow the network to be up to
1 km with changes in the termination resistance, cabling, number of nodes and data rate.

This flexibility in CAN network design is one of the key strengths of the various extensions and additional standards that have been built on the original ISO 11898 CAN standard.