Diodes are one-way valves for electricity. They allow current to flow in one direction only, making them essential for power conversion and circuit protection.
How a Diode Works
A diode has two terminals: Anode and Cathode. When the anode is at a higher potential than the cathode, the diode conducts electricity. When the polarity is reversed, it blocks current.
This behavior is called Forward Bias and Reverse Bias.
Types of Diodes
- Standard PN Junction Diode – Used in rectifier circuits.
- Zener Diode – Conducts in reverse beyond breakdown voltage for voltage regulation.
- Schottky Diode – Low forward voltage drop, ideal for power circuits.
- Light Emitting Diode (LED) – Emits light when forward biased.
- Photodiode – Converts light into electrical current.
Key Specifications
- Forward voltage (≈ 0.7V for silicon)
- Reverse leakage current
- Maximum reverse voltage
- Switching speed
Applications
- AC to DC conversion (rectification)
- Voltage regulation
- Reverse polarity protection
- Signal demodulation
- Optical communication
Diodes are foundational components in both analog and digital electronics. Understanding their behavior improves circuit efficiency and reliability.