1N4148

The 1N4148 is a standard silicon switching diode. It is one of the most popular and long-lived switching diodes because of its dependable specifications and low cost. Its name follows the JEDEC nomenclature. The 1N4148 is useful in switching applications up to about 100 MHz with a reverse-recovery time of no more than 4 ns. The 1N4148 comes in a DO-35 glass package for through-hole mounting. This is useful for breadboarding of circuits. A surface mount device, 1N4148WS, is available in a plastic SOD package.

As the most common mass-produced switching diode, the 1N4148 replaced the older 1N914, which had a 200 times greater leakage current: 5 µA vs. 25 nA. Since leakage is usually an undesirable property, today manufacturers produce the 1N4148 and sell it as either part number. It was second-sourced by many manufacturers; Texas Instruments listed their version of the device in an October 1966 data sheet. These device types have an enduring popularity in low-current applications.