• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 18 subscribers
  • Views 1407 views
  • Users 0 members are here
Support feedback
Options
Options

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN7406: function table

Michael T Schneider
Expert 3780 points
Part Number: SN7406
Other Parts Discussed in Thread: SN74LS06

The two ICs in questions are SN7406 and SN74LS06D.  They both claim to have a High-Level output voltage of 30 Volts, but according to the function table of the SN74LS06D a TTL low would be Hi-Z, not a high output.  Am I interpreting this wrong?  The SN7406 looks like the function table would be:

Input A

Output Y

H

L

L

H

 But I’m not sure if I’m misinterpreting the Y=Abar

On Page 8 of the SN74LS06D there’s the following function table.

 

The SN7406 has the following logic diagram on sheet 2.

Thanks,

  • 0
    Guru 293610 points

    Both the SN7406 and SN74LS06 have open-collector outputs:

    An open-collector output can never drive a high voltage, so the function table showing "Hi-Z" is correct.

    However, the most common thing you do with an open-collector output is to connect a pull-up resistor, so in practice, there will be a high voltage at the pin. The primary difference from a totem-pole output is that that high voltage is imposed by the external circuit, and can be different from the 5-V VCC.