How to measure open-drain vs. hi-z with multimeter

Question

I have an output pin configured to be either open-drain or hi-z. How can I use my multimeter to tell which mode it is in?

Can you make sure the output value is low while you do the test? — The Photon, Dec 23 '13 at 18:02
Also, what device are you using? Is it a microcontroller or an FPGA or something else? A link to the datasheet of the device would give us the most information to help answer your question. — The Photon, Dec 23 '13 at 18:05

score 4 · Accepted Answer · answered Dec 23 '13 at 18:09

4

If the pin can only be high impedance or open collector then you can add a pullup resistor to the pin and try to write a logic 0 to it, If the pin voltage goes low it is open-collector, if it stays at a high voltage then it is high impedance.

answered Dec 23 '13 at 18:09

Joe Hass

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How to measure open-drain vs. hi-z with multimeter

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