Bipolar Transistors The development of transis

The development of transistors in the late 1940s has had a tremendous impact on technological progress. The components are able to control electric power. Moreover, transistors can be easily fabricated and incorporated into complex electronic circuits. In recent years, high speed bipolar technologies have been developed for use in mainframe computers, analog-digital applications, and high speed electronic circuits.

Bipolar or junction transistors are similar to diodes. Diodes are formed by the junction of P-type and N-type semiconductor material. In contrast, bipolar transistors are composed of two such junctions. These two junctions combine to form a "'sandwich' of semiconductor material" (Olesky, 1992, pp. 39-47).

In the early years, germanium was primarily used to construct bipolar transistors. Later, however, silicon transistors were developed. The performance of silicon transistors was found to be less affected by changes in temperature. More recently developed bipolar transistors may incorporate both germanium and silicon, as well as polysilicon. Through the use of polysilicon, shallower transistor junctions have been manufactured. Such technologies have led to a reduction in transistor dimensions (Nakamura & Nishizawa, 1995, pp. 390-397).

The three basic components of bipolar transistors include the collector, base, and emitter. The diode formed by the base-emitter junction forms the input to the transistor. The base

Related Essays

Electrical Engineering Reference Manual .... pp. 8-16 to -18); bipolar junction transistors (having two opposing PN junctions)(pp. 8-18 to -23); small-signal amplifiers (pp. .... (4954 20 )

The Transistor .... There are many kinds of transistors, and this paper will look at one called .... are analogous to the emitter, collector, and base of a bipolar transistor (American .... (1873 7 )

oupling capacitors can open, become leaky, or short. Open capacitors may block a-c signals. In addition, defective biasing resistors may alter transistor regulation. Such defects can significantly affect transistor collector-emitter voltages. According to the rules of electronic troubleshooting, a transistor with an abnormal collector-emitter voltage, VCE, should be tested for either an open or a short. Voltage measurements at the collector of an open transistor should give VCE = VCC. In contrast, the voltage across a shorted transistor will be equal to zero. If the transistor is neither open or short, then the biasing circuit components should be checked for possible malfunctions. The bipolar transistor is an important component of many different circuits. The devices are useful for controlling current flow. Moreover, they can significantly amplify supply voltages. These various functions have undoubtedly contributed to their widespread application in electronics. References Levi, A. F. J.; Nottenburg, R. N.; Chen, Y. K., & Panish, M. B. (1990, February). Ultrahigh-speed bipolar transistors. Physics Today, 43, 58-64. Nakamura, T., & Nishizawa, H. (1995, March). Recent progress in bipolar transist

Category: Science - B