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SN65LBC173A-EP: Schmitt triggers on the inputs?

Michael T Schneider
Expert 3780 points
Part Number: SN65LBC173A-EP

Team, 

I had a question about this RS-485 receiver. Does this part have Schmitt triggers on the inputs? I see the logic diagram with the Schmitt symbol, but no mention of it anywhere in the datasheet.

Also, I was wondering under what conditions, the high level output voltage sags to 2.7V. I’m driving a CMOS voltage translator, so it won’t be drawing much current, but was curious since there wasn’t a graph of this in the datasheet.

  • +1
    TI__Mastermind 46687 points

    Hi Michael,

    They are Schmitt Trigger inputs 

    Typically there is 40mV of hysteresis between positive and negative going thresholds.

    For your second question:

    Essentially temperature is the main culprit -  as this increases the effective output resistance and this is also going to be at minimum rec. voltage so 4.75V VCC. This is a worst case scenario (highest temp; lowest VCC) which leads to more loss on the output resistance and a smaller voltage source to drive the output. It is not a common occurrence and realistically you should be looking at closer to typical conditions unless you are maxing out the recommended range. 

    Please let me know if you have any other questions!

    Best,

    Parker Dodson