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On the one hand, I really like this article in general. It's a pretty clear explanation of how transistors work physically, without requiring too much knowledg
by ajdecon 16y ago
On the one hand, I really like this article in general. It's a pretty clear explanation of how transistors work physically, without requiring too much knowledge of semiconductor physics. Though I don't think he introduced the idea of holes very well.
On the other hand: the whole article is written in a style that suggests this is some kind of major revelation to someone with a background in electrical engineering. I really find that hard to believe: is this really never explained in EE courses? I'm a physics major turned materials scientist, and this is really well-understood in both of those communities. HN EE's, did you all never get a course in solid state physics or electronic materials?
Which isn't an insult: I can understand that this kind of understanding might not be essential to circuit design, though I might think it would help. But if this is seriously not something they teach EE's, you're missing out. Because solid state physics is some seriously cool shit.
- woodrow 16y agoThis isn't a major revelation, at least to me (trained as a CompE with EE tendencies), but I will agree that I've never heard a really good, intuitive explanation of how a bipolar junction transistor works, despite modeling and working with them as current-controlled current amplifiers, as the author mentions. This especially obvious in contrast with MOSFETs, which are IMO easy to understand intuitively.
- borisk 16y agoFor an electrical engineer transistor is a black box 99.9% of the time. It's enogh to know it's interface.
- deleted 16y ago[deleted]
- philwelch 16y agoEE is a huge field. One of my recently-graduated friends is going to grad school to be an analog engineer, and this kind of thing is his bread and butter. Other EE's not necessarily.
- _delirium 16y agoI think it varies by program. I was a CS major, but at the school I went to, EE was actually not that far away from us. I tend to think of circuits as sort of ground-zero of most EE programs, and then some programs push more downwards in the abstraction hierarchy, covering solid-state physics and similar, while others (like ours) push more up the abstraction hierarchy, covering more CEish topics like chip design, pipelining, even up to embedded-systems programming (there was also a very strong focus on signal processing). Ideally I guess you'd want to know everything, from fundamental physics to CS, but a 4-year program sort of has to pick some subset.
- zb 16y agoAlthough borisk is correct that engineers mostly work at higher layer of abstraction, this absolutely was taught when I was at engineering school. What's more, there was a detailed discussion of transistor geometry, which is fairly critical but elided completely in this explanation, presumably because it's hard to draw ASCII art pictures of it.
- Pyrodogg 16y agoI was in a CompE program a year ago. I didn't take semiconductors but I'm pretty sure it was required of the EEs at some point.
- wbeaty 16y agoFor an interesting experience, ask a group of EEs if bipolars are inherently current-controlled devices. This tends to create long-running flamewars (similar effect to asking pilots how airfoils create lift.) The ones who know that bipolars are current-controlled will nearly come to blows with the ones who know that they're voltage controlled. Very strange, but not unexpected when considering the poor jobs textbooks do with the non-math intuitive explanations. See sci.electronics.design for multiple examples of such fights, also wikipedia discussion history.