• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 20 subscribers
  • Views 450 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

SN74LVC1G175: Impedance of the Q output pin?

Mark Franklin
Prodigy 30 points
Part Number: SN74LVC1G175

That's it ... need to know the impedance of the Q output pin, since this circuit will sometimes see +5Vdc from the USB port.

  • 0
    TI__Mastermind 24975 points
    Hello Mark,

    So in your case my understanding is that you want to know the impedance to ensure that the current is limited.
    While you can calculate the maximum possible impedance from the datasheet. Based on VOH/VOL and the corresponding load current, we don't have any information that says what the minimum impedance would be.
    Therefore for a system design where the output voltage could have bus contention, it is best to assume the output impedance to GND or VCC is essentially 0 depending on the output state of the device.

    If you want to make sure the device does not fail due to the output shorting to 5V, it is best to have a current limiting resistor in series with the output to ensure that when this 5V dc case happens, the current is limited to within the recommended operating conditions for IOL or IOH.

    I hope this helps, let me know if you have additional questions.

    Best,
    Michael