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SN65HVD3082E: Alternative without external pulldown resistor

Bernahrd Zigler
Prodigy 10 points
Part Number: SN65HVD3082E
Other Parts Discussed in Thread: THVD1500

Tool/software:

Hello,

Is there an alternative, pin-compatible type to SN65HVD3082ED that does not require an external pulldown resistor?

Best regards.

  • 0
    Guru 284830 points

    The DE pin has an internal pull-down. Why do you think than an external one is necessary?

    Most RS-485 transceivers use a standard pinout; there is no reason not to use the more modern THVD1500.

  • 0 in reply to Clemens Ladisch
    Prodigy 10 points

    Thank you very much for the quick response.

    I expressed myself poorly.
    I need an alternative to SN65HVD3082ED, as it is no longer up-to-date.

    Based on the datasheet and the described circuitry, I assumed the need for an external resistor.
    The datasheet for the THVD1500 series shows and describes the same schematic.

    Please clarify if I have misinterpreted something in the datasheet.

    Thank you very much.

  • 0 in reply to Bernahrd Zigler
    Guru 284830 points

    The datasheet says:

    Use 1-kΩ to 10-kΩ pullup and pulldown resistors for enable lines to limit noise currents in theses lines during transient events.

    This is independent from the transceiver used. If your environment does not have much noise, you do not need them.

  • 0 in reply to Bernahrd Zigler
    TI__Guru 60540 points

    Hi Bernahrd,

    As Clemens has stated the recommended device is THVD1500. You should be able to move to this device without any changes to your circuit.

    Both devices have internal resistors on the #RE/DE pins that disable themselves upon power up.

    The THVD1500 has better typical hysteresis, has ESD ratings, fault protection, and wider temperature support than the previous device.

    -Bobby