SLLSF98 December   2018 SN55HVD233-SEP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Driver Electrical Characteristics
    6. 7.6  Receiver Electrical Characteristics
    7. 7.7  Driver Switching Characteristics
    8. 7.8  Receiver Switching Characteristics
    9. 7.9  Device Switching Characteristics
    10. 7.10 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Modes
      2. 9.3.2 Loopback
      3. 9.3.3 CAN Bus States
      4. 9.3.4 ISO 11898 Compliance of SN55HVD233-SEP
        1. 9.3.4.1 Introduction
        2. 9.3.4.2 Differential Signal
          1. 9.3.4.2.1 Common-Mode Signal
        3. 9.3.4.3 Interoperability of 3.3-V CAN in 5-V CAN Systems
      5. 9.3.5 Thermal Shutdown
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Diagnostic Loopback
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Slope Control
        2. 10.2.2.2 Standby
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Bus Loading, Length, and Number of Nodes
      2. 12.1.2 CAN Termination
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Receiving Notification of Documentation Updates
    2. 13.2 Community Resources
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

10.2.2 Detailed Design Procedure

Table 4. Suggested Cable Length vs Signaling Rate

BUS LENGTH (m) SIGNALING RATE (Mbps)
40 1
100 0.5
200 0.25
500 0.1
1000 0.05

Basically, the maximum bus length is determined by, or rather is a trade-off with the selected signaling rate as listed in Table 4.

A signaling rate decreases as transmission distance increases. While steady-state losses may become a factor at the longest transmission distances, the major factors limiting signaling rate as distance is increased are time varying. Cable bandwidth limitations, which degrade the signal transition time and introduce inter-symbol interference (ISI), are primary factors reducing the achievable signaling rate when transmission distance is increased.

For a CAN bus, the signaling rate is also determined from the total system delay – down and back between the two most distant nodes of a system and the sum of the delays into and out of the nodes on a bus with the typical 5-ns/m prop delay of a twisted-pair cable. Also, consideration must be given the signal amplitude loss due to resistance of the cable and the input resistance of the transceivers. Under strict analysis, skin effects, proximity to other circuitry, dielectric loss, and radiation loss effects all act to influence the primary line parameters and degrade the signal.

A conservative rule of thumb for bus lengths over 100 m is derived from the product of the signaling rate in Mbps and the bus length in m, which should be less than or equal to 50.

Signaling Rate (Mbps) × Bus Length (m) ≤ 50. Operation at extreme temperatures should employ additional conservatism.