diode 1. diode applications 2 diode symbols 3 i-v characteristic 4

Diode

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Diode applications

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Diode symbols

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I-V characteristic

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Testing diode

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Temperature effects

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Diode datasheet

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Ideal diode

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Ideal half wave rectifier

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Solar Cell (photovoltaic cell)

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Light Emitting Diode (LED)

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Infrared LED (IR LED)

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Photodiode

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IR LED + Photodiode application

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Schottky diode I-V characteristics

Schottky diode is a metal-semiconductor (MS) diode Historically, Schottky diodes are the oldest diodes MS diode electrostatics and the general shape of the

MS diode I-V characteristics are similar to p+n diodes, but the details of current flow are different.

Dominant currents in a p+n diode arise from recombination in the depletion layer under

small forward bias. arise from hole injection from p+ side under larger

forward bias. Dominant currents in a MS Schottky diodes

Electron injection from the semiconductor to the metal.

Zener diode

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What is a Zener Diode?: A Zener diode is a special case of  ordinary semiconductor silicondiode.  Specifically, the Zener displays the following property: The direction of current is from positive to negative and it blocks current in the minus to plus direction (Reversed Bias). See sketch for Zener diode symbol and picture of markings on a part itself. If a positive voltage is applied to the anode terminal of a Zener diode and a negative voltage is applied to cathode terminal, the Zener diode will behave as an ordinary semiconductor diode.  However, when a positive voltage is applied to the negative, the Zener diode will breakdown when it is reversed biased by a voltage greater than the breakdown voltage. As a result a Zener voltage (Vz) will appear across the diode terminals, with its cathode being positive and the anode being negative.See Figure below for pictorial and associated symbol:See example below for more informationIn the preceding figure which reflects a zener diode acting as a zener voltage regulator across load resistor R2.

Zener diode

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Filter Smoothes out pulsating dc but still some time-

dependent components-(ripple) remain in the output

Voltage Regulation Reduces ripples Stabilizes magnitude of dc output against variation in

load current Regulation by Zener Diode or Voltage regulator I.C

Rectifier Circuits