- It is a specially designed diode which is optimized to operate in breakdown region.
- Zener diode is silicon diode.
- By varying the doping level silicon diode, a manufacturer can produce zener diodes with breakdown voltage from about 2 to 200V.
Applications of Zener Diodes
- As voltage stabiliser
- For meter protection
- For wave shaping
- Varactor diode operates under reverse biased conditions.
- Varactors are silicon diodes optimized for their variable capacitance.
- These diodes are voltage controlled diode.
- These diodes are used in television receiver, FM receivers, automobile radios and other communication equipment.
Light Emitting Diodes (LEDs)
- These are made from gallium arsenide phosphide (GaAsP) and Gallium phosphide (GaP).
- LEDs have a typical voltage from 1.5V to 2.5V for currents between 10mA to 50mA.
- LEDs have longer life, more than 20 years.
- They use in panel indicators, digital watches, calculators, multimeters, intercoms etc.
- It is also known as photodectector.
- Photodiode is optimized for its sensitivity to light.
- Photo diode operates under reverse biased conditions.
- Schottky diode is a special purpose diode.
- For its construction, a metal like gold, silver or platinum is used on one side of the junction and doped silicon is used on the other side.
- Schottky diode can easily rectify signals of frequency above 300MHz without distortion.
- These diodes are best suited for low voltage rectification.
- Schottky diodes find their best application in these computers because of their fast operation.
- These diodes are also used for rectification of high frequency (50MHz to 500MHz) signals such as in digital computers.
- By increasing the doping level, we can get breakdown at 0V, such diodes are known as tunnel diodes.
- This diode has negative-resistance region.
- The tunnel diode is useful in high-frequency oscillatory circuits.