SLLSFS1B August   2023  – April 2024 THVD4431

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  ESD Ratings [IEC]
    4. 5.4  Recommended Operating Conditions
    5. 5.5  Thermal Information
    6. 5.6  Power Dissipation
    7. 5.7  Electrical Characteristics
    8. 5.8  Switching Characteristics_RS-485_500kbps
    9. 5.9  Switching Characteristics_RS-485_20Mbps
    10. 5.10 Switching Characteristics, Driver_RS232
    11. 5.11 Switching Characteristics, Receiver_RS232
    12. 5.12 Switching Characteristics_MODE switching
    13. 5.13 Switching Characteristics_RS-485_Termination resistor
    14. 5.14 Switching Characteristics_Loopback mode
    15. 5.15 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Integrated IEC ESD and EFT Protection
      2. 7.3.2 Protection Features
      3. 7.3.3 RS-485 Receiver Fail-Safe Operation
      4. 7.3.4 Low-Power Shutdown Mode
      5. 7.3.5 On-chip Switchable Termination Resistor
      6. 7.3.6 Operational Data Rate
      7. 7.3.7 Diagnostic Loopback
      8. 7.3.8 Integrated Charge pump for RS-232
    4. 7.4 Device Functional Modes
      1. 7.4.1 RS-485 Functionality
      2. 7.4.2 RS-232 Functionality
      3. 7.4.3 Mode Control
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Data Rate and Bus Length for RS-485
        2. 8.2.1.2 Stub Length for RS-485 Network
        3. 8.2.1.3 Bus Loading for RS-485 Network
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2 Protection Features

The THVD4431 bus pins are protected against any DC supply shorts in the range of -16 V to +16 V. In the RS-485 mode, the short circuit current is limited to ±250 mA to comply with the TIA/EIA-485A standard. In RS-232 mode, current limiting of ±60 mA is applicable for scenarios where bus pins can short to ground.

The device also features thermal shutdown protection that disables the driver and the receiver if the junction temperature exceeds the TSHDN threshold due to excessive power dissipation on-chip.

Supply undervoltage protection is present on both VCC and VIO supplies. This maintains the bus output and receiver logic output in known driven state when both the supplies are above their rising undervoltage thresholds. Table below describes the device behavior in various scenarios of supply levels.

Table 7-1 Supply Function Table
VCC VIO Driver Output Receiver Output
> UVVCC(rising) > UVVIO(rising) For RS-485 mode, determined by DIR and L3 inputs. For RS-232 mode, determined by L3, L4, L6 inputs. For shutdown mode, Hi-Z For RS-485 mode, determined by DIR and (R1-R2) or (R3-R4) inputs. For RS-232 mode, determined by R1, R2, R5, R7, R8 inputs. For shutdown mode, Hi-Z
< UVVCC(falling) > UVVIO(rising) High impedance Undetermined
> UVVCC(rising) < UVVIO(falling) High impedance High impedance
< UVVCC(falling) < UVVIO(falling) High impedance High impedance