What is the two main function of a diode?
Main functions The most common function of a diode is to allow an electric current to pass in one direction (called the diode’s forward direction), while blocking it in the opposite direction (the reverse direction). As such, the diode can be viewed as an electronic version of a check valve.
What is the main function of zener diode?
Zener diodes are used for voltage regulation, as reference elements, surge suppressors, and in switching applications and clipper circuits. The load voltage equals breakdown voltage VZ of the diode. The series resistor limits the current through the diode and drops the excess voltage when the diode is conducting.
What are the advantages of Zener diode?
Advantages of Zener Diodes
- Less expensive than other diodes.
- Ability to shift voltage.
- Easily compatible and obtainable across systems.
- High-performance standard.
- Protection from over-voltage.
- Ability to regulate and stabilize circuit voltage.
- Greater control overflowing current.
- Usable in smaller circuits.
How much current can a Zener diode handle?
Zener diode specifications Voltage Vz: The Zener voltage refers to the reverse breakdown voltage—2.4 V to about 200 V; can go up to 1 kV while the maximum for the surface-mounted device (SMD) is about 47 V). Current Iz (max.): Maximum current at the rated Zener voltage Vz—200 uA to 200 A).
What is a Schottky Rectifier?
The Schottky diode or Schottky Barrier Rectifier is named after the German physicist “Walter H. Schottky”, is a semiconductor diode designed with a metal by the semiconductor junction. It has a low-forward voltage drop and a very rapid switching act. Actually, it is one of the oldest semiconductor devices in reality.
What is called Zener breakdown?
The process in which the electrons move across the barrier from the valence band of p-type material to the conduction band of n-type material is known as Zener breakdown.
What is Zener tunneling?
1. It is a reverse breakdown mechanism in which high electric field generated at P-N junction, electrons tunnel from the valence band to conduction band of a semiconductor device.
What happens at zener voltage?
When the voltage across the terminals of a Zener diode is reversed and the potential reaches the Zener Voltage (knee voltage), the junction breaks down and the current flows in the reverse direction. This effect is known as the Zener Effect.
How is zener voltage calculated?
Zener diodes have voltage values from less than 2 volts to several hundred volts, and they can dissipate power ranging from 0.25 to 50 watts… or more. Using the formula of power Pz = Vz x Iz, you can get the maximum current that can pass through a zener diode: Iz = Pz/Vz.
What is Zener point?
The voltage point at which the voltage across the zener diode becomes stable is called the “zener voltage”, ( Vz ) and for zener diodes this voltage can range from less than one volt to a few hundred volts.
What happens at knee voltage?
Knee voltage is the forward voltage at which the flow of the current through the PN junction of the diode increases rapidly.
What happens if a diode is reversed?
Reverse bias usually refers to how a diode is used in a circuit. If a diode is reverse biased, the voltage at the cathode is higher than that at the anode. Therefore, no current will flow until the electric field is so high that the diode breaks down.
Why do we need knee voltage?
Once the light-emitting diode is connected to an external voltage in the forward bias, the potential barrier height across the PN junction will be decreased. This exact voltage is known as the knee voltage of the LED. Thus, this is all about knee voltage and the difference between breakdown voltage.
What is minimum power rating of Zener diode?
Current : The current, IZM, of a Zener diode is the maximum current that can flow through a Zener diode at its rated voltage, VZ. Typically there is also a minimum current required for the operation of the diode. As a rough rule of thumb, this can be around 5 to 10 mA for a typical leaded 400 mW device.
Can zener diode handle high current?
Current : The current, IZM, of a Zener diode is the maximum current that can flow through a Zener diode at its rated voltage, VZ. Typically there is also a minimum current required for the operation of the diode….Zener diode specifications.
| Zener Diode Voltage Values in E12 Range | ||
|---|---|---|
| 3.3 | 3.9 | 4.7 |
| 5.6 | 6.8 | 8.2 |
How is zener diode power calculated?
Power is calculated by multiplying current by voltage (P=IE), so we can calculate power dissipations for both the resistor and the Zener diode quite easily: A Zener diode with a power rating of 0.5 watts would be adequate, as would a resistor rated for 1.5 or 2 watts of dissipation.