5 ms·
A transistor is not two diodes back-to-back. It may be literally true that a transistor is two P-N junctions, but if you think of a transistor this way, you'll
by ta150418 10y ago
A transistor is not two diodes back-to-back. It may be literally true that a transistor is two P-N junctions, but if you think of a transistor this way, you'll never understand them. The magic of the transistor is that if the P-N junctions are close enough together, you get transconductance -- when either junction is forward-biased, current can flow between the collector and emitter. Diodes don't do this!
- CarolineW 10y agoSee my comments here: https://news.ycombinator.com/item?id=11522126 https://news.ycombinator.com/item?id=11522126 You are right about the difference, you are wrong when you say that thinking about them like this will mean I'll never understand them. It's the merging of the N (or P) bands that makes the magic of a transistor happen, but not thinking of them as diode-like junctions means you're only thinking about them one way, not as an integrated concept. We are probably in violent agreement, but I suggest that if you only understand diodes as diodes and transistors as transistors, you are limiting your points of view, and potentially not seeing the whole picture.
- simcop2387 10y agoIn fact looking at them as a diodes can let you use some bjts to get a fast low leakage diode in a pinch. http://electronics.stackexchange.com/questions/16966/transistor-as-low-leakage-diode http://electronics.stackexchange.com/questions/16966/transis...