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I found this post: Is there a popular small signal PFET equivalent to NFETs 2N7000 or BS170?

It is stated there that BS250 can be used as complementary to 2N7000. In my local stores I can not find BS250, but I can find BS250P, though price is quite high.

Question #1: can I use BS250P as complementary to 2N7000?

Question #2: are there any other alternatives to BS250, which are complementary to 2N7000 and comes in TO-92 case?

In case I can not use BS250P and other alternatives are not available/unreasonably expensive in my local shop,

Question #3: could you please suggest pair of commonly used mosfets in TO-92 case to make logical inverter? I need it to work on +12V with input signal from 0 to +12V. Frequency range is from 33 (most likely) to 100 kHz.

winny
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Alex
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  • CD4007. It has two mosfet pairs and one inverter. Safe to use up to 18V. If you just need +12V logic, you may use any of the CD4xxx circuits. – Janka Jun 16 '21 at 22:52
  • You need to provide a list of all PMOS devices that are available in your local shop that you consider to be reasonably priced. Otherwise we would be wasting our time. You don't expect us to guess, do you? – Elliot Alderson Jun 17 '21 at 00:19
  • @Elliot Alderson, this list would contain hundreds of mosfets. I don't think this is good idea :) Its big shop (unfortunately it doesn't have English interface), but for now I know only one coplement - BS250, which they don't sell. If you could provide several options off the top of my head, I could check if they have any. Btw, can I consider BS250P as complementary to 2N7000? – Alex Jun 17 '21 at 07:32
  • I forgot to mention, that I'm looking for mosfet in TO-92 case to make soldering easy – Alex Jun 17 '21 at 07:34
  • @Janka, thank you, I will take a look at CD4xxx. I need something easy to mount on wire. 2 MOSFETS would be great for me. Well, maybe something in tiny soic or dip case will also be fine. Anyway, thank you for idea, I will take a look if there is anything in CD4xxx which I can use. – Alex Jun 17 '21 at 07:45
  • Local store and TO-92 is making life very hard for yourself when the rest of the world has moved forward to SMD. – winny Jun 17 '21 at 09:57
  • @winny, I have device, which output I need to invert. I planned to cut some paths and solder solution based on TO-92. That's why SMD is not suitable in my case. Unfortunately. – Alex Jun 17 '21 at 11:42
  • Is it a one-off job? If you can't get it in the capsule you want, I would consider deadbuging it and glue it in place. – winny Jun 17 '21 at 12:02
  • @winny, yes, it is one-off job. I planned to use heat-shrink tube to cover TO-92 transistors and use wires to solder transistors with rest device. Sorry, by "deadbuging" you mean destroy case of ic and take its internals out? Or I misunderstood you? :) – Alex Jun 17 '21 at 12:10
  • No. Flip it over so the legs are pointing up, glue it down and run wires from each leg. Buy a transistor with sufficiency low RdsON to not have to care about heatsinking. Photo examples: http://uydudoktoru.com/threads/lipoly-low-battery-indicator.30354/, http://electronics.stackexchange.com/questions/31504/qfp-on-stripboard-without-pcb – winny Jun 17 '21 at 12:16
  • Ah, now I see why it is called "deadbugging" ))) Well, it is also an option. Probably I will use it in case I will not find transistor in TO-92 case. Or may be I will use something like IRF7309 (but faster) if I will find way to mount it in safe way. But I still have hope to find something in TO-92 :) So, noone still answered, can I consider BS250P as complementary to 2N7000 or not? I guess not? – Alex Jun 17 '21 at 12:28
  • Why are you so in love with TO92? If you need to cut tracks anyway, this will be a hack job. Go with the flow. – winny Jun 18 '21 at 13:21
  • @winny, my device is very tiny and there is not much space to mount extra SMD components. Because of that TO92 would be better option (easier to mount). I'm also OK with any other case, which is easy to mount – Alex Jun 21 '21 at 18:15
  • Deadbug! Hot melt glue! Anyone of these should do it for you: https://www.digikey.com/en/products/filter/transistors-fets-mosfets-single/278?s=N4IgjCBcoGwAwyqAxlALgJwK4FMA0IA9lANogDMAHAKxhzkgC6BADmlCAMqYCWAdgHMQAXwIwwAJiQhUkTLgLFIZSXADsMAJwgCYACzUJYCLr1xqayjvBhKYcdbCby6tY7hwD2gpr0w9JiA0an6O%2BhZuBJaaxtZ6elTketYuEjAS3hRwTvTWGeROyQQSlCGGeZTZFnmWdNQ1lWqZEpbqiMUwLnDNFnpqUsW9MFbFCTRWzCBsHNwY-EKi4BkQ0DLo2PhEpCBm1OSambsBcHHmZtqT05BcvIIixQhWq7Lym0pkLgAEAGopEj8pcgAghJYEUahg8gwSGUMFmOFA34EAxwzRg6hwAGXdjXACqfB4aAA8gAzACyOAAhgBnLAYHD3EAAWikz3WCi2yhA9UYwj5QA – winny Jun 21 '21 at 18:48
  • I wonder which wankr downvoted this useful question? – onepound Sep 19 '22 at 20:00

1 Answers1

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For those, who will have the same question in future:

In specified conditions (12 V, 33 kHz) BS250P can be used as complementary for 2N7000. I was able to create logical inverter using these transistors and everything works as expected.

Alex
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