SLLSFQ4A September   2022  – March 2023 THVD1424

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  ESD Ratings [IEC]
    4. 6.4  Recommended Operating Conditions
    5. 6.5  Thermal Information
    6. 6.6  Power Dissipation
    7. 6.7  Electrical Characteristics
    8. 6.8  Switching Characteristics_500 kbps
    9. 6.9  Switching Characteristics_20 Mbps
    10. 6.10 Switching Characteristics_Termination resistor
    11. 6.11 Switching Characteristics_Duplex switching
    12. 6.12 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagrams
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 On-Chip Switchable Termination
      2. 8.4.2 Operational Data rate
      3. 8.4.3 Protection Features
  9. 9 Application Information Disclaimer
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Data Rate and Bus Length
        2. 9.2.1.2 Stub Length
        3. 9.2.1.3 Bus Loading
        4. 9.2.1.4 Receiver Failsafe
        5. 9.2.1.5 Transient Protection
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

9.2 Typical Application

An RS-485 bus consists of multiple transceivers connecting in parallel to a bus cable. To eliminate line reflections, each cable end is terminated with a termination resistor, RT, whose value matches the characteristic impedance, Z0, of the cable. This method, known as parallel termination, allows for higher data rates over longer cable length. THVD1424 has on-chip 120 Ω termination resistor well suited for most commonly used cables for RS-485 applications. Figure 9-1 shows two end nodes terminated, while remaining nodes unterminated. THVD1424 can be designed in all node designs. TERM_TX pin allows configuring the nodes for end nodes and middle nodes in the network.

Figure 9-2 shows termination on end nodes of each pair of cable in a full duplex network. Once again, THVD1424 makes it possible to have common board design for all nodes. TERM_TX and TERM_RX pins allow configuration for end nodes and middle nodes.

GUID-20220729-SS0I-5DVV-RJTM-TKNDJVP8HMFF-low.svg Figure 9-1 Typical RS-485 Network With THVD1424 configured in Half-Duplex mode
GUID-20220729-SS0I-KKL5-LPGN-BDPXWPFXQR1L-low.svg Figure 9-2 Typical RS-485 Network With THVD1424 configured in Full-Duplex mode