21 Dec
2007
21 Dec
'07
3:26 p.m.
Do all
transsitors have to be of the same flavour, or could I use TUNs
and TUPs?
I'd never encountered the TUN & TUP TLAs before, so I looked them up:
Transistor, Universal NPN/PNP. Neat!
And any TUN or TUP will do, provided a device of comparable spec was
reasonably available to hobbyists in the mid sixties. For my first
efforts, at least, I'll be using the PN2222 in modern TO-92 plastic
Sure. I tened to use 2N3904/2N3906 to excess round here. I don't think
they're quite the same spec as a TUN.TUP, but they're pretty universal in
their own right :-).
packages. I'm not sure when the TO-92 package was
introduced, but
there were definitely plastic package transistors available then.
SOTs are right out, though :)
Given that there's a limit on the number of transistors, I don't see what
advantage using SOT23s would give you. OK, you could make it smaller,
maybe clock it faster. But the change in package wouldn't allow a totally
different architecture. So I don't see any particular reason to ban them,
since the same design could be built with compoents in 1960's packages.
-tony