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logic low on 9476 seems high

I'm supplying 12 V to my 9476 (and have verified this by measuring at the pins). When I toggle any one of my DO channels I see the 12 V when I'm at logic high, but when I set it to low I'm seeing about 7.75 V. I wouldn't be surprised, I suppose, to see some amount of voltage when low, but that's nearly 2/3 or the supplied voltage. I have some level shifters that some of these channels are connected to and that 8V is preventing the shifted voltage from being anything but logic high.

 

So my questions:

  • When I output a zero on one of my 9476's lines is it actually supposed to output a low level or is it instead floating the line (and therefore requires a pulldown resistor at the output)?
  • If it is supposed to output an actual voltage, why on earth is it so high relative to the Vsup?

Thanks!


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