The TO-220 is a type of semiconductor package that is commonly used for medium to high-power transistors, voltage regulators, and integrated circuits. The acronym "TO" stands for "Transistor Outline," and "220" refers to the specific package style as per the JEDEC standard.
TO 220
The TO-220 package is a through-hole package, which means it's designed to be inserted into drilled holes in printed circuit boards (PCBs) and then soldered into place. It typically has three leads and a metal tab, which is often used as a heat sink to help dissipate heat away from the device.
This heat sink capability makes the TO-220 package suitable for components that generate considerable heat, such as power transistors and voltage regulators. It's widely used in power management applications because of its good heat dissipation properties.
As always, for specific information such as pin assignment, electrical characteristics, or precise physical dimensions, refer to the manufacturer's data-sheet for the specific device in question.