[Physics Class Notes] on Uses of Zener Diode Pdf for Exam

We know about the employment of Zener Diode which is to allow the current stream in forwarding or invert course. Zener Diode is a semiconductor gadget consisting of a P-N intersection that leads the current in a switch course when a specifically determined voltage is reached. 

It has a converse breakdown voltage which implies it can constantly work in an opposite predisposition mode without getting harmed. A Zener Diode does not just permit current to move from anode to cathode yet in addition, in the opposite bearing on arriving at the Zener voltage. Because of this usefulness, Zener Diodes are the most generally utilized semiconductor diodes.

In the device, a reverse-biased, strongly doped p-n junction diode operating in the breakdown region is utilized. In the breakdown zone, conventional diodes and rectifiers are never used, but the Zener diode can be safely employed at the designated point.

It has a reverse breakdown voltage, which implies it can function in an opposite tendency condition for an unlimited period without being destroyed.

To obtain the Zener voltage, a Zener Diode permits the current to flow not only from anode to cathode but also in the opposite direction. Due to their versatility, Zener diodes are the most commonly used semiconductor diodes.

Zener Diode – Functions and Applications

• When in forward-bias mode, the Zener diode works just like a regular diode, with a turn-on voltage of between 0.3 and 0.7 V. In any case, when converse one-sided voltage is applied to the Zener diode, it works in various ways. 

• A current begins to flow through the diode when the reverse voltage reaches the predetermined breakdown value (Vz). Now, a little expansion in invert voltage will quickly expand the electric flow. On account of this abrupt ascent in electric flow, a breakdown happens called Zener breakdown. Nonetheless, Zener Diode displays a controlled breakdown that harms the gadget.

• At the point when opposite one-sided voltage is applied to a Zener Diode, it permits just a modest quantity of spillage current until the voltage is not exactly Zener voltage. At the point when the converse one-sided voltage applied to the Zener diode comes to Zener voltage, it begins permitting an enormous measure of electric flow. 

Zener Breakdown

The Zener breakdown effect, which occurs below 5.5 V, or impact ionization, which occurs above 5.5 V, causes the breakdown. The same behavior can be obtained by both processes. They also do not necessitate any additional circuitry. However, the temperature coefficient of each mechanism is different

The temperature coefficient of the Zener effect is negative, whereas the temperature coefficient of the impact effect is positive.

At 5.5 V, the two temperature effects are nearly equivalent and cancel one other out. It makes 5.5 V Zener diodes the most stable over a wide variety of temperature settings.

Applications

Zener Diode is a Voltage Controller: At the point when the heap voltage approaches the breakdown voltage, the resistors which are associated in arrangement restrict the current through the diode when there is an abundance measure of voltage while the diode is leading. 

While doing that the diode produces some sort of commotion which can be smothered by adding enormous worth decoupling capacitors across the Diode. The heap voltage rises to the breakdown voltage VZ of the Diode. The arrangement resistor restricts the current through the Diode and drops the overabundance voltage when the Diode is directed. 

Overvoltage Protection

The current through the diode generates a drop across the resistor as the voltage rises to the Zener breakdown value. This results in a brief descent to the bottom.

When the information voltage exceeds the Zener breakdown voltage, current flows through the diode, causing a voltage drop across the resistor, activating the SCR, and generating a short to ground. The breaker is opened by the short out, which separates the heap from the inventory.

Switching a signal from one voltage to the next is the most common application for Zener Diodes. In breakdown regions, it can maintain a constant yield voltage. The Zener Diode is an ideal component of the activity due to its voltage-moving usage.

Zener Diode is utilized to Cut Circuits 

Trimmer circuits are utilized to keep the yield signal from going past a decided incentive without transforming anything of the info signal. Employment of Zener Diode incorporates adjusting and moulding the AC waveform cutting circuits. The section circuits restrict one piece of the AC waveform to shape the waveform or give security. 

These sorts of circuits are by and large utilized in TV and FM transmitters for eliminating obstruction. Zener Diodes are utilized to alter or shape AC waveform cutting circuits. The cut-out circuit cutoff points or clasps off pieces of either of the half patterns of an AC waveform to shape the waveform or give insurance.