From Wikipedia, the free encyclopedia
Jump to: navigation, search
BD135 NPN transistor in a TO-126 package.

TO-126 is a type of semiconductor package for devices with three pins, such as transistors.[1] The package is rectangular with a hole in the middle to allow for easy mounting to a board or a heat sink.

History and origin[edit]

The JEDEC TO-126 descriptor is derived from the original full name for the package: Transistor Outline Package, Case Style 126. In the updated JEDEC outline system, the package is numbered as TO-225AA.[2]

See also[edit]


  1. ^ BD135; BD137; BD139; NPN power transistors (PDF), Philips Semiconductors, 1999, retrieved 2013-12-09 
  2. ^ AN1040/D: Mounting Considerations For Power Semiconductors (PDF), On Semiconductor, 2001, retrieved 2014-01-25