Transistor pinout

[pittsallen@usa.net]

Hello Electronic Circuits Help Forum,

With the flat facet of the TO-92 package facing you
and the three legs pointing down the transistor in the data sheet
http://www.nxp.com/documents/data_sheet/PN2222A.pdf
marked PN2222A has the collector on the left
the base in the middle and the emitter on the right.

With the flat facet of the TO-92 package facing you
and the three legs pointing down the transistor in the data sheet
https://www.fairchildsemi.com/datasheets/PN/PN2222A.pdf
marked PN2222A has the collector on the right
the base in the middle and the emitter on the left.

So do different manufacturers have different pinouts for
a transistor with the same name?
Is the base always in the middle?

Without the datasheet is there a way of knowing which
pin has which function?

Thanks.

Allen in Dallas

[pebe]

So do different manufacturers have different pinouts for
a transistor with the same name?

Both the manufacturers you quote are using the same pinouts for the PN2222A.

Is the base always in the middle?

There are other TO-92 pinouts that are different. Have a look at the 2N3902, where the base and collector are swapped over.

[KMoffett]

I ran into this a while ago. The 2N2222A and PN2222A are one way...the P2N2222A is the opposite.
Note the drawing on the right side. http://en.wikipedia.org/wiki/2N2222
But, if you do a Google search on the P2N2222A it's shown both ways.

Ken