• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 18 subscribers
  • Views 154 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

SN74AHC14: Is it OK to connect 1K pull up resistor to 5V at the output of SN74AHC14PWR powered by 3.3V?

Qi Liu
Intellectual 2610 points
Part Number: SN74AHC14

Hi, support team

My customer has the questions as follow:

Is it OK to connect 1K pull up resistor to 5V at the output of SN74AHC14PWR powered by 3.3V?

Thanks so much.

Best regards,
Yuki

  • 0
    TI__Intellectual 2610 points

    In addition, what the meaning of output clamp current (IOK)?

  • 0
    Guru 262940 points

    The clamp current is the current that flows from the I/O pin into VCC (or, for negative voltages, from GND out of the I/O pin).

    With the 1kΩ resistor, the current is limited to about 1.2 mA, which is OK.

    However, the 3.3 V supply must be able to sink this current. If this is not the case, the supply voltage will float up, and all devices connected to that 3.3 V supply might be damaged.

    A device with open-drain outputs would not have these problems.