1. Zener Diode
By Dr. Vaibhav Jain Associate Professor, Dept. of Physics, D.A.V (PG) College, Bulandshahr, U.P., India.

2. Zener Diode
Zener Diode : Works in the break down region when subjected to reverse bias.
Large variation in current. Voltage almost constant.
Used for voltage regulation. Upper limit of current depends on the power dissipation rating of the device.

3. Zener Diode
Zener diode

4. Series voltage regulator

5. Zener diode is a diode that block current until a specified voltage is applied. Remember also that the applied voltage is called the breakdown, or Zener voltage. Zener diodes are available with different Zener voltages. When the Zener voltage is reached, the Zener diode conducts from its anode to its cathode (with the direction of the arrow).
In this voltage regulator, Q1 has a constant voltage applied to its base.

6. This voltage is often called the reference voltage
This voltage is often called the reference voltage. As changes in the circuit output voltage occur, they are sensed at the emitter of Q1 producing a corresponding change in the forward bias of the transistor.
In other words, Q1 compensates by increasing or decreasing its resistance in order to change the circuit voltage division.

7. V-I Characteristics of Zener Diode

8. V-I Characteristics of Zener Diode
Zener diodes are manufactured to have a very low reverse bias breakdown voltage
Since the breakdown at the zener voltage is so sharp, these devices are often used in voltage regulators to provide precise
voltage references. The actual zener voltage is device dependent. For example, you can buy a 6V zener diode.

9. Thank You