• TI Thinks Resolved


Prodigy 20 points

Replies: 3

Views: 71

Part Number: AM26LV31E-EP


we are having two modules each module is having am26lv31e  driver which drives rs485 signals. at the destination there is single receiver. our application is such that one module is driving rs 485 signals other module should be in high impedance. if we short both the driver op's to destination is it going to work?can we use EN/EN- to make drivers active and high impedance?

attachment shows our application.System 1 RS422.docx

  • Harikrishnan,

    First off, the AM26LV31/2  are RS422 driver/receivers.  They are not RS485.  They are similar specifications.

    The leakage presented to the bus is listed in the datasheet (disabled for IOZ), and similarly Io(off) for power off case.  Both indicate +/= 127uA for the driver.

    This is a common usage.

    One possible concern is location of the termination.   Ideally they should be at the furthest endpoints of the bus.  The stubs to the drivers/recievers should be kept short to minimize reflections.

    If your system requires RS485, you will want to select another driver receiver pair that is RS485 compliant.

    If this answers your question, please click "This Resolved My Issue"

  • In reply to Wade Vonbergen:


    Thank you for your reply. so AM26LV31/2 are only RS422 driver/receiver,so if we change our communication protocol to RS422 whether the application will work?Can RS422 support multiple drivers on the bus to single reciever?

    if not can you suggest some RS485 driver/receiver from ti?

  • In reply to harikrishnan i:

    RS422 and RS485 are similar.  RS485 is more robust.

    You can choose an RS485 device from this parametric tool.  The list will include both RS422 and 485.  Select from the ones with RS485 in the device description.

    Use the filters on the left to narrow down choices.