Baby Mark King Size Low-Profile Through-Hole Transistor For Cigarette Machines

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. Transistors are one of the basic building blocks of modern electronics. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit.

Mass Production

In the 1950s, Egyptian engineer Mohamed Atalla investigated the surface properties of silicon semiconductors at Bell Labs, where he proposed a new method of semiconductor device fabrication, coating a silicon wafer with an insulating layer of silicon oxide so that electricity could reliably penetrate to the conducting silicon below, overcoming the surface states that prevented electricity from reaching the semiconducting layer. This is known as surface passivation, a method that became critical to the semiconductor industry as it later made possible the mass-production of silicon integrated circuits.

Importance

Transistors are the key active components in practically all modern electronics. Many thus consider the transistor to be one of the greatest inventions of the 20th century.

The invention of the first transistor at Bell Labs was named an IEEE Milestone in 2009. The list of IEEE Milestones also includes the inventions of the junction transistor in 1948 and the MOSFET in 1959.

Voltage Drop

The image represents a typical bipolar transistor in a circuit. A charge will flow between emitter and collector terminals depending on the current in the base. Because internally the base and emitter connections behave like a semiconductor diode, a voltage drop develops between base and emitter while the base current exists. The amount of this voltage depends on the material the transistor is made from and is referred to as VBE.