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SN65HVD82: SN65HVD82

Kailyn Chen
Genius 9560 points

Part Number: SN65HVD82

Hello,

When the SN65HVD82 power up, all the input and output ports are float,  what is the Pin D  voltage value?

The input equivalent circuit is as follows, Pin D is pulled high to VCC, but the tested voltage is about 1/2 Vcc.

Best regards

Kailyn

  • 0
    TI__Mastermind 25705 points

    Kailyn,

    You're right. If SN65HVD82 is fully powered up, D should be pulled to Vcc by internal circuitry. Can you describe the way you measure the voltage? Do you use a multimeter or scope? Where is the grounding? What's the input impedance of the equipment? Can you also check DE and REB pins?

    Regards,

    Hao

  • 0 in reply to Hao L
    TI__Genius 9560 points

    Hi Hao,

    Our customer used a scope and tested the value of the Pin D is about 1/2Vcc when  SN65HVD82 is fully powered up and D is float. I will confirm with the customer of the RE and DE voltage. Do you have any suggestions? 

    Best regards

    Kailyn

  • 0 in reply to Kailyn Chen
    TI__Guru 62920 points

    Hi Kailyn,

    The internal pull-up uses a high resistance, so the pin voltage could easily be pulled down by external leakage currents.  Do you have an estimate of the loading introduced by the measurement (e.g., multimeter input or oscilloscope probe) and anything else connected to the pin (e.g., MCU GPIO)?

    Regards,
    Max