Diodes, Transistors and Thyristors

Arrow.com is an authorized distributor of diodes, transistors and thyristors from leading manufacturers including onsemi, Diodes Incorporated, Nexperia, Microsemi, Infineon, Vishay, STMicro and more. Shop a huge selection of bipolar, FET and IGBT transistors, rectifiers, regulator and RF diodes, and thyristors for every application.

Diodes, transistors, and thyristors are all types of semiconductor devices. A diode is a two-terminal device that exists anywhere p-type and n-type semiconductors are directly adjoined to each other. Applying a positive voltage to the anode will not produce any significant current until the diode's threshold voltage is exceeded. Once the threshold voltage is exceeded current will be allowed to flow from the anode to the cathode but the diode will block current flow from the cathode to the anode under most conditions. They are used in AC-DC transformers, radios, electro-static discharge (ESD) circuits, as light sources, etc.

Transistors are three-terminal devices that can be made in bipolar junction (BJT) form, or more commonly as complimentary metal-oxide-semiconductor (CMOS). They are created by adjoining n-type and p-type semiconductors in either the PNP or NPN configuration. Typically a voltage is applied to a gate terminal allowing current to flow through the device where the transistor functions similarly to a switch. They are used in digital systems to implement logic gates and store data. Analog circuits use them to create amplifiers and oscillators.

A thyristor is another three-terminal semiconductor device that acts as a bistable switch. It conducts once its gate is charged and continues to conduct while forward biased. They are built from four adjoined semiconductors in NPNP or PNPN format. They are often used in circuits with relatively large amounts of power. Unlike a transistor, a thyristor can only function as a digital switch.