This document discusses Zener diodes. It begins with an introduction to diodes in general and then focuses on Zener diodes. Key points covered include: the electric symbol and parameters of a Zener diode; the forward and reverse voltage-current characteristics; advantages like voltage regulation and disadvantages like power waste; circuit tips for using Zener diodes as voltage regulators; and references for further information. The document aims to provide an overview of Zener diodes, their characteristics and applications.

1. Zener Diode
University of Development
Alternative (UODA)
Submitted To:
Farzana Rahman
Mishu
Sr. lecturer
Submitted By:
Kaniz Fatema Chaity
Sharmin Sultana
Dept. of Computer Science &
Engineering
Faculty of Engineering

2. Topic’s Covered
 What is Diode?
 Different types of Diode
 What is Zener Diode?
 Parameters
 V-I characteristics
 Advantages & Disadvantages
 Zener Diode as voltage regulator
 Circuit tips
 Reference

3. What is Diode?
• A diode is a semiconductor device with two terminals,
typically allowing the flow of current in one direction only.

4. Different types of Diode

5. What is Zener Diode?
Electric Symbol
Figure: Zener Diode

6. Parameter
 Breakdown Voltage - UZ
 Breakdown Current - IZ
 Forward Bias Voltage - UF
 Reverse Current – IR
 Voltage Stabilization Factor

7. V-I characteristics
The V-I Characteristics of a Zener Diode can be divided into two parts:
Forward Characteristics
Reverse Characteristics

8. Advantages & Disadvantages
Advantages:
Control of flowing current
Size and Expense
Performance
Compatibility and Obtainability
Disadvantages:
Zener diodes cancel out voltages by applying even larger voltages in the reverse
direction, wasting electricity in the process. Additionally, Zener diodes have a relatively
poor regulation ratio and are generally not as good as transistors.

9. Zener Diode as Voltage regulator

10. Circuit tips
 Choose correct voltage for best stability
 Buffer the Zener diode circuit with an emitter or
source follower
 Drive with constant current source for best
stability
 Ensure sufficient current for reverse breakdown
 Ensure maximum limits of current are not exceeded for
the Zener diode

11. Reference
 Wikipedia.com
 http://whatis.techtarget.com
 http://www.instructables.com/id/Types-of-Diodes
 http://www.reuk.co.uk/What-is-a-Zener-Diode.htm
 http://www.radio-electronics.com/info/data/semicond/diodes/types-of-diodes.php
 http://blog.oureducation.in/v-i-characteristics-of-zener-diode
 http://www.allinterview.com/showanswers/143751/what-are-advantage-
and-disadvantage-of-zener-diode.html
 http://www.electrical4u.com/zener-diode-symbol-and-application-as-
voltage-regulator/
 http://www.radio-electronics.com/info/data/semicond/zener-voltage-
reference-diodes/applications-circuits.php

13. Created by Mohammad Ali Khan
Dept. of Computer Science & Engineering
Faculty of Engineering
University of Development
Alternative (UODA)
Created by Mohammad Ali Khan
Dept. of Computer Science & Engineering
Faculty of Engineering
University of Development
Alternative (UODA)