Transistor Packages Outlines

Obsolete JEDEC Designations

This page holds a few additional transistors outlines that are obsolete. Package outlines that use low number JEDEC designations, used by early transistors no longer in production. Because these packages are so old, only the outline drawing is provided. The actual physical dimensions are available but not provided here to reduce server bandwidth.

TO-9 Outline

TO-9 Case Package
TO-9 Package Drawing

The 2N1500 general purpose transistor used the TO-9 package. A 3-terminal metal can similar to many other device still in production. The transistor leads are identified in the drawing, located by the metal tab at the base of the can [which is optional]. The leads are insulated from the case.

TO-11 Outline

The 2N341 general purpose, low power transistor used the TO-11 package. Another 3-terminal metal-can similar to the TO-9 outline shown above. A drawing of the TO-11 is provided on the main page covering Transistor Case Outlines [not repeated here to save bandwidth].

TO-12 Outline

The 3N35 general purpose, low power transistor used the TO-12 package. A 4-terminal metal can similar to a few other device outlines. The transistor leads are identified in the drawing, which is always the bottom view looking up into the pins. The tab on the case locates the pins. Note that this package uses two individual Base leads [Base 1 & Base 2]. The leads are electrically isolated from the metal case.

TO-12 Case Package
TO-12 Package Drawing

TO-44 Outline

The T0-44 had an elongated metal shell, much taller than the normal metal-cans that are commonly found. A drawing of the TO-44 is provided on the main page covering Transistor Case Outlines [not repeated here to save bandwidth]. The TO-44 package was used by a 2N384 which was a high frequency PNP transistor.

Package Obsolescence

As already indicated these JEDEC package designations are out-dated, or inactive. The precise date the designations were withdrawn for use is not known. The transistor part numbers provided as examples are certainly obsolete and no longer being manufactured. The graphics provide the general shape, or outline of the component as defined by the JEDEC designation. It would seem that after most of the electronics industry moves on to a new package style, and many of the packages that used the outline are out of production, the designation is retired. Meaning the call-out is no longer used for new devices, but may still be used by older products still in production.

Editor Comment; I did want to cover these packages, but by using the smallest amount of bandwidth possible. So the symbol table which defines the physical dimensions, common on all the other case outline pages, is absent here. Although the tables are some what small in physical size, they still have to be down loaded to be viewed. Any component covered by these transistor outlines should have pulled from service long ago, decades ago.

Obsolete Package Styles

Related topics:
JEDEC Case Outlines
Manufacturers of BJTs

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Modified 6/13/15
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