Baritt diode – Working and Applications: The barrier-inject transit time (BARITT) diode is basically a back-to-back pair of diodes biased into reach-through condition. It belongs to the transit-time microwave diode family. In this diode microwave oscillation occurs due to the thermionic injection and diffusion of minority carriers across the forward-biased barrier and a 3π/2 transit …
What is a thermistor? – Definition, Symbol and V-I Characteristics: The word thermistor is a combination of thermal and resistor. A thermistor is a resistor with definite thermal characteristics. Most thermistors have a negative temperature coefficient, but positive temperature coefficient devices are also available. The reason of negative temperature coefficient of resistance of a semiconductor …
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Varistors or Voltage Dependent Resistors (VDRS): Varistors, also called the voltage dependent resistors (VDRs), show a high degree of nonlinearity between their resistance value and the applied voltage. They are made of non-homogeneous materials giving a rectifying action at the contact of two particles. Various materials, such as silicon carbide, zinc oxide, are used to …
Power Diode – Structure, Symbol, Characteristics and Types: Diodes find many applications in electronics and electrical engineering circuits. Power diodes play a significant role in power electronics for conversion of electric power. A diode acts as a switch to perform various functions, such as switching in rectifiers, freewheeling in switching regulators, charge reversal of capacitor …
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What is Backward Diode? A tunnel diode designed to provide a small peak current (IP of the order of IV) may be employed to advantage in the reverse direction, for purposes for which the conventional diode is used in the forward direction. Because this device is a better conductor in the reverse direction than in …
What is Schottky Diode? – Definition, Symbols and Construction: At lower frequencies, an ordinary diode can easily turn off when the bias changes from forward to reverse. But with the increase in frequency the diode reaches a point where it cannot turn off fast enough to prevent noticeable current during part of the reverse half …
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Fast Recovery Diode (FRD): Fast recovery diode are designed to provide ultrahigh switching speed. The devices can be classified into two types : diffused P-N junction diodes and metal semiconductor diodes. The equivalent circuit of both types can be represented by the varactor diode [Fig. 8.41 (b)]. The total recovery time for a P-N junction …
What is Step Recovery Diode? – Working and Applications: What is Step Recovery Diode? – It is also a voltage dependent variable capacitor diode but with unusual doping profile. It has concentration of charge carriers decreasing near the junction, as illustrated in Fig. 8.46, and therefore, a phenomenon, called the reverse snap-off is caused. It …
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Point Contact Diode Construction and Working: The point contact diode is basically constructed by touching a metallic whisker to an exposed surface of an N-type semiconductor substrate. The semiconductor used in the point contact diode may be either of germanium or of silicon. However, germanium is preferred over silicon because of its higher carrier mobility. …
Tunnel Diode Construction and Working: Tunnel Diode Construction and Working – The tunnel diode (sometimes called the Esaki diode after its inventor, Dr. Leo Esaki) is a high conductivity, heavily doped two-terminal P-N junction. This diode differs from the normal P-N junction diode in the amount of impurity concentration. The impurity concentration in a normal …