1N400x rectifier diode

[2][3] Diodes with similar ratings are available in SMA and MELF surface mount packages (in other part number series).

[4][5] The 1N540x (or 1N5400) series is a similarly popular family of diodes rated 3 Amperes, which has a larger DO-201AD axial package to dissipate heat better.

[6][7] The 1N400x series was originally introduced by Motorola's Semiconductor Products Division and registered at JEDEC in 1963 as silicon power rectifiers used primarily for military and industrial applications.

[14] [verification needed] They are not designed for switching applications; datasheets often do not specify any information on their turn-on and turn-off characteristics.

[16] The following table lists part numbers in the 1N400x, 1N540x, and other popular general-purpose silicon rectifier diode families.

1N4001 diode in DO-41 axial package (through hole mount)
A schematic symbol for general-purpose silicon rectifier diodes
Current-voltage characteristics of a 1N4001 at different temperatures