I just thought of an instance where that's not true, even for an ordinary MOSFET... suppose NF (number of "fingers") is an odd number?
Then capacitances and series (bulk) resistances are asymmetric.
In my chip design, my (netlisting) templates account for that, but most simulators don't automatically do that.
...Jim Thompson
Now you are the authority? OK, I'm right and you don't matter.
There is here. And in Cambridge.
at
The "proper" IGBT symbol is even sillier than the mosfet thing, right up there with the ghastly IEC logic symbols, which I assume you use.
I don't use IGBTs (too slow!) but I would draw one exactly the way that I draw n-mosfets.
Luckily, I get to make the rules here.
You might ask the guys who invented the thing and published the first suggested symbol.
I don't have the ref handy, but I'm sure Bill could pull up something from IEEE.
I know how you trust Sloman's authority, so that should be more than good enough...
Tim
Nope. The emitter is the "richest" doping concentration, the base is second and the collector is third... that's why inverse beta is quite a bit smaller than forward... beta is a function of the ratio of "emitter" doping concentration to that of the base.
It is possible, using implant techniques, to make symmetrical BJT's, say for sampling switches... but MOS devices beat BJT's at that application, so they are rare devices anymore.
Yes ...Jim Thompson
On Fri, 28 Aug 2015 12:33:28 -0700, Jim Thompson Gave us:
Read up on the finFET.
he
m
I used one of the original Fairchild FI-100 p-channel MOSFET parts in my Ph .D. project. The symbol in my thesis isn't the one I'd use now, with the ar row on the source bar rather than the substrate bar, but it's presumably wh at I got from the Fairchild data-sheet, back around 1967.
Them proposing a symbol doesn't make it the only right one. It just makes it a proposed symbol.
NT
I had lunch once with Walter Brattain but didn't think to ask how he drew transistors. I think some of the early symbols were weird.
It's too late now.
Sure, he does a lot of electronic design.
the
om
dVery little that John Larkin can understand. His project turn-around time a pparently averages at a fortnight. Mine tended to be a couple of years.
He thinks he does innovative design, but it's more accurate to call it incr emental development. "Intelligent design" also comes to mind, which is the way fundamentalists want to see Darwinian evolution - which is actually a p rocess of mindlessly throwing out random variations and keeping the ones th at more or less work.
Bill Sloman, Sydney
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