SDAA526 September   2026 THVD4431A

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2THVD4431A RS-485 Half-Duplex Operation
    1. 2.1 Mode Configuration
    2. 2.2 Driver Disable Timing
  6. 3System-Level Transient Behavior
    1. 3.1 What Is Observed
    2. 3.2 Why It Occurs
  7. 4Design Recommendations
    1. 4.1 Increase Differential Bus Capacitance
    2. 4.2 Add Bus Biasing Resistors
    3. 4.3 Ferrite Bead Selection
    4. 4.4 Software Consideration
  8. 5Summary
  9. 6References

4.4 Software Consideration

Because the transient occurs only during the DIR transition period when the receiver is being enabled, the UART of the MCU is typically not actively sampling. If the transient is captured by the UART, firmware can be configured to ignore the RX signal during the direction-change window as a temporary workaround.