How is a Zener diode constructed?

How is a Zener diode constructed?

Construction of Zener diode The junction region is covered with a layer of silicon dioxide (SiO2). At the same time during construction, the whole assembly is metallised in order to generate anode and cathode connection. The layer of SiO2 helps to prevent contamination of the junctions.

What is Zener diode explain its construction and working?

The Zener diode is a special kind of heavily doped PN junction diode designed to conduct in reverse the reverse direction when a certain specified voltage reached. It is a silicon semiconductor switch that permits the current to flow in both directions, either a forward or reverse direction.

How are diodes constructed?

A diode is formed by joining two equivalently doped P-Type and N-Type semiconductor. At the point of contact of the P-Type and N-Type regions, the holes in the P-Type attract electrons in the N-Type material. Hence the electron diffuses and occupies the holes in the P-Type material.

Where does Zener diode come from?

A Zener diode is a silicon semiconductor device that permits current to flow in either a forward or reverse direction. The diode consists of a special, heavily doped p-n junction, designed to conduct in the reverse direction when a certain specified voltage is reached.

How do you calculate Zener current?

The maximum current is calculated by dividing the power rating by the Zener voltage: I=P/V = 3W/12V = 0.25A.

How does Zener diode works?

The Zener diode operates just like the normal diode when in the forward-bias mode, and has a turn-on voltage of between 0.3 and 0.7 V. As the reverse voltage increases to the predetermined breakdown voltage (Vz), a current starts flowing through the diode.

What is an ideal Zener diode?

Pin configuration. Anode and cathode. Electronic symbol. A Zener diode is a special type of diode designed to reliably allow current to flow “backwards” when a certain set reverse voltage, known as the Zener voltage, is reached.

What is Zener diode?

How diodes are constructed and perform in general?

Diodes can be made of either of two semiconductor materials, silicon and germanium. Power diodes are usually constructed using silicon. When the cathode voltage is more positive than the anode, the diode is said to be reverse-biased, and it blocks the current flow.

How is zener voltage calculated?

The 3SMAJ5927B is a 12 V Zener diode in a 3 W package. It’s knee current, breakdown current, or minimum current is 0.25 mA. The maximum current is calculated by dividing the power rating by the Zener voltage: I=P/V = 3W/12V = 0.25A.

How does the Zener diode work in a short circuit?

Zener diode is connected parallel to the load to make it reverse bias and once the Zener diode exceeds knee voltage, the voltage across the load will become constant. When the input voltage is higher than the Zener breakage voltage, the voltage across the resistor drops resulting in a short circuit.

When does Avalanche occur in a Zener diode?

The avalanche effect occurs in both rectifier and Zener diodes at a sufficiently high reverse voltage. On the other hand, Zener breakdown occurs in a Zener diode at low reverse voltages. A Zener diode is heavily doped to reduce the breakdown voltage.

How does reverse bias affect the Zener diode?

In the reverse bias condition the Zener diode is an open circuit and only a small leakage current is flowing as shown on the exaggerated plot. As the breakdown voltage is approached the current will begin to avalanche. The initial transition from leakage to breakdown is soft but then the current rapidly increases as shown on the plot.

What happens when the Zener voltage is reversed?

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.