Diode
A diode is an electronic component that allows current to flow in only one direction. It acts like a valve: it lets electricity pass in one direction but blocks it in the other. It consists of two terminals: the anode (positive side) and the cathode (negative side).
That said, there are several types of diodes. Observe the different types along with their corresponding symbols:
Types of Diodes:
1)- Standard (Silicon) Diode.
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Used for rectifying current (e.g., in power supplies).
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Example: Diode bridge circuit (converts AC to DC).
2)- Zener Diode.
- Allows current to flow in reverse once a certain voltage is exceeded → used for voltage regulation.
Example: Simple Zener-based voltage regulator circuit.
3)- LED (Light Emitting Diode).
- Emits light when current passes through it.
4)- Schottky Diode.
- Very low forward voltage drop (~0.15V to 0.4V).
- Extremely fast switching → ideal for high-speed circuits.
5)- Varicap (Varactor Diode).
- A diode whose capacitance changes based on the applied reverse voltage.
- Operation:
- Acts like a variable capacitor.
- The reverse voltage adjusts the depletion region width, altering capacitance.
Main Uses: - Tuning circuits in radios & TVs.
- Voltage-controlled oscillators (VCOs).
- Has largely replaced mechanical variable capacitors.
6)- Photodiode.
- A semiconductor component that converts light into electric current.
7)- Tunnel Diode (Esaki Diode)
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A unique semiconductor device that uses quantum tunneling to exhibit negative resistance.
Key Features:- Negative resistance → Useful in oscillators & amplifiers.
- Extremely fast switching → Suitable for high-frequency applications.
- Low power consumption.