TO-53 Metal Can
Transistor Can Package TO-52 Case style, Metal Can
TO-52 Metal Can Physical Dimensions
The TO-52 package is a 3 pin metal can. This is a through-hole component.
Terminal Identification; Lead 1, Emitter. Lead 2, Base. Lead 3, Collector [The collector is electrically connected to the case]. Lead assignments are provided for a transistor, but a FET may also be found using this package style. Note that some data sheets may refer to the TO-52 package as a 2-leaded package because the third lead is connected to the case. However this same case style may be found with only 2 physical leads.
There are a number of other transistor packages that use this same style, but differ in their physical dimensions. Refer to the Transistor Cases link to review additional transistor packages. A few other components are listed here that also use the TO-52 case, which only serve to show a similar device in a compatible package. That being a direct physical replacement, and perhaps with similar electrical characteristics.
As of 1996 JEDEC considers the TO-52 inactive for use and has removed the designation. However that does not stop a manufacturer from continued use of the package type. Or does not stop a manufacturer from continuing to offer a device in the TO-52 package style.
Editor note; Although not referenced here a 2-pin version is also possible, if the manufacturer decided to omit a terminal.
