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From: whit@milton.u.washington.edu (John Whitmore)
Newsgroups: sci.electronics
Subject: Re: Transistor help
Summary: 2N numbers are JEDEC-registered three-terminal devices
Message-ID: <9451@milton.u.washington.edu>
Date: 18 Oct 90 01:00:26 GMT
References: <44900014@uxa.cso.uiuc.edu>
Organization: University of Washington, Seattle
Lines: 34

In article <44900014@uxa.cso.uiuc.edu> smlg1015@uxa.cso.uiuc.edu writes:
>
>Could someone explain what devices are included under the 2N. . . numbers?

	All '2Nxxxx' numbers are issued by JEDEC (Joint Electronic
Devices Engineering Council, I think), and relate to any three-terminal
electronic widgets.  Transistors, FETs, SCRs, unijunction transistors,
etc.
>Are they all BJT's or  FET's, as well ?  
	Obviously, no.
> Do all American/ Japanese transistor
>manufacturers label using the 2N. . . numbers?  

	Most Japanese manufacturers don't, and many US manufacturers have
large numbers of unregistered devices.  Registration makes it possible
for your competitors to sell the same devices (i.e. it makes the device
number generic).  For some reason, most plastic power transistors
and lots of consumer-equipment transistors are of unregistered types.
	Japan has its own registered-part system, with 2SAxxx, 2SBxxx, ...
type numbers; this system DOES have a separate set of numbers for
FETs and bipolar transistors.

>Can you get any information off the 2N. . . number without a spec sheet?

	Not much; if the number is low (2N500 or below) it's almost
certainly Ge; if it's high (2N2000 or above) it's probably Si;
and if it has a 2Nxxxx part number, it can't be a dual-gate MOSFET;
that's because dual-gate MOSFETs have four terminals, not three;
they get 3Nxxx part numbers, instead.  Some optoisoolators have a
three-terminal transistor and two-terminal LED, so have 4Nxx 
numbers.


	John Whitmore