RS-485 Automatic Direction Control Reference Design
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Key Document


The TIDA-01090 reference design enables half-duplex communication over an RS-485 bus without requiring additional driver-enable/receiver-enable controls.  The design allows for the transceiver used on each node to go into transmit mode automatically when data is being transmitted from a local Microcontroller (MCU) or Universal Asynchronous Receiver/Transmitter (UART) and then transition back into receive mode once the data frame is complete.

  • Automatically enables an RS-485 driver when data is output from an MCU or UART
  • Transitions RS-485 transceiver into receive mode when data is not being transmitted
  • Works with any RS-485 transceiver
  • Low-cost due to minimal number of components
  • Adjustable data frame length via passive component selection

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Schematic/Block Diagram

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Design Guide

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Design Files

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TI Devices (2)

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Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
NA555  Precision Timers  Clocks & timing  Sample & Buy Not Available
SN65HVD3082E  Half-duplex RS-485 transceiver  Interface  Sample & Buy View Design Kits & Evaluation Modules

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
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SN65HVD3082E Download Download
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Technical Documents

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User guides (1)
Title Type Size (KB) Date
PDF 2835 02 Jun 2016
Design files (6)
Title Type Size (KB) Date
ZIP 0 21 Jun 2016
ZIP 298 21 Jun 2016
PDF 421 21 Jun 2016
PDF 70 21 Jun 2016
PDF 96 21 Jun 2016
PDF 54 21 Jun 2016

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