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I stumbled upon a weird transistor or resistor component which I can't place. Here is a simplified version of the circuit:

weird transistor

I am pretty sure that the transistor on the bottom is an N-MOS transistor which pulls out low if in is high. The weird component at the top seems to serve as pull up resistor but looks more like a transistor than anything.

Can someone identify the component?

Note: I saw the component on a presentation slide which I don't have access to. I had recreated the circuit from my notes, and thus can't provide more information.

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    \$\begingroup\$ The resistor at the top could be a potentiometer. Without seeing the original circuit, it'd just be a guess though. Any idea what the application was? As for the bottom component, while it could be a mosfet, its a very strange way of drawing it, so again, the whole circuit, or the original would be needed to make a better guess. \$\endgroup\$
    – MCG
    Jun 4 '19 at 13:19
  • \$\begingroup\$ @mcg I am very bad at drawing; the lines on the bottom are supposed to be zigzag like the symbol of a resistor. It was used just like that, the only difference was that there were a lot of transistors in parallel between out and ground (I only drew one). \$\endgroup\$
    – asynts
    Jun 4 '19 at 13:23
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    \$\begingroup\$ How certain are you that they were transistors? The resistor component could be a potentiometer, which could mean it was used as a pullup, although it doesn't make sense why it wouldn't be a fixed resistor, which makes it a bit confusing for me, so I wouldn't like to say for sure. Is there no way you can get hold of the original? I think it would be a big help for clarification \$\endgroup\$
    – MCG
    Jun 4 '19 at 13:26
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    \$\begingroup\$ Possibly a "pinch resistor". \$\endgroup\$ Jun 4 '19 at 13:45
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    \$\begingroup\$ context would help \$\endgroup\$
    – Russell McMahon
    Jun 4 '19 at 14:14
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Looks like NMOS transistor being used in depletion mode as an active resistive pull-up.

See Wikipedia: Depletion-load NMOS logic.

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  • \$\begingroup\$ That must be it. "[...] A depletion-mode device with gate tied to the opposite supply rail is a much better load than an enhancement-mode device, acting somewhere between a resistor and a current source. [...]" from the wikipedia article. \$\endgroup\$
    – asynts
    Jun 4 '19 at 13:33

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