TO-220 pinout standard?

[[email protected]]

Is it standard that a TO-220 transistor package is, with the tab up,
with the markings facing you, Base, Collector, Emitter? (for example,
on the TIP31A)

I noticed the TO-92 2N3904 I have is (with the markings facing me) E B
C, and a TO-92 2N2222 data sheet even shows C B E !!!

Michael

 

[[email protected]]

The TO-220 package is used for many devices not just transistors.
The pinout is what the data sheet says it is.
Always consult the data sheet if the leads are not marked.

Tom

So does this mean it is NOT standard that a TO-220 *transistor*
package is BCE? (with the markings facing you)

Michael

 

[[email protected]]

You will find some that are not that way.

Tom

Thanks.

Michael

 

[neon]

2N3904 is in a TO18 casing

 

[Eeyore]

Is it standard that a TO-220 transistor package is, with the tab up,
with the markings facing you, Base, Collector, Emitter? (for example,
on the TIP31A)

For pcb layout ? I like to make the central pin 0.1" ? Forward of the
other two. When unheatsunk it also gives greater mechanical stability.

It gives greater pad clearance too.

Graham

 

[Eeyore]

So does this mean it is NOT standard that a TO-220 *transistor*
package is BCE? (with the markings facing you)

BCE to me, then which way are you looking at it ? READ THE DATASHEET.

Grahan

 

[Eeyore]

You will find some that are not that way.

Like FETS !

Graham

 

[Eeyore]

It is _common_ for a TO-220 transistor to be wired that way, but not
universal.

The manufacturer will pin out the transistor in the way they think is
best; usually this means connecting the collector to the tab for good
heat dissipation, and to the center pin because that's what wants to
connect to the tab (I don't know why center pin = tab; I assume it's for
some sound mechanical reason).

It's the bulk of the die substrate.

Graham