Page 70 - Make Your Own PCBs with EAGLE from Schematic Designs to Finished Boards

Transistors and Diodes

Through-hole diodes have similar footprints to resistors. Transistors are a bit more complex,
especially power transistors that need to dissipate some heat.

Through-Hole Transistors

By far the most commonly used package for through-hole transistors is the TO-92 package. Higher-
power transistors generally will use a TO-220 package, although intermediate-sized packages are
occasionally used, as well as occasionally large packages such as the TO-3 for very high-power
devices. Figure 3-7 shows a selection of through-hole transistor packages. These are (left to right)
TO-92, TO-126, TO-220, TO-264, and TO-3. Table 3-5 shows the two most commonly used

packages and their footprints.