Transistor information

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Miracletech

Joined Nov 15, 2019
29
While doing a research on an electronic circuit, i found out that transistor pins may vary depending on manufacturer. Is this true and how?
 

SamR

Joined Mar 19, 2019
1,295
Or use one of the cheap chinese M-Testers and it will identify them. Much quicker for me than looking up the PDF. I always keep one handy. Even within the same Model such as the 2n2222 and 2n2222a they mixed up the pins causing headaches.
 

dl324

Joined Mar 30, 2015
9,122
i found out that transistor pins may vary depending on manufacturer. Is this true and how?
Parts with the same part number will have the same pinout.

Without more specific information, your question can't be answered definitely.

That said, there are 3 pinout for transistors in TO-92, those used by 2N*, BC*, and 2S*.
 

dl324

Joined Mar 30, 2015
9,122
I wish the "BC" Europeans, "2N" Americans and "2S" Orientals got together about little transistor pinouts.
Or labeled the pins. I have some Motorola 2N3904 and 3906 that have the leads labeled. I also have house marked Motorola PNP transistors that have the leads labeled.
 

DickCappels

Joined Aug 21, 2008
5,938
Wait! There is more!

Some RF transistors have the emitter in the middle so the emitter and its PCB traces can act as a shield to reduce capacitive feedback (Miller effect). BobaMosfet was right "...you always look at the datasheet."
 

Wolframore

Joined Jan 21, 2019
1,320
You should be able to identify the base using a meter but you can’t always tell emitter from collector. The meter method assumes the base emitter junction has larger depletion layer than the base collector... hmmm interesting, not sure I would rely on that.
Just look up the datasheet...

you can’t just replace a MOSFET where there was a BJT, They have different requirements and biasing requirements.
 
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