1. Diode & its Applications Presented by D.Satishkumar Asst. Professor, Electrical & Electronics Engineering Email: iamdsk.d@gmail.comiamdsk.d@gmail.com Contact No: +919591578732

2. Introduction: Diode The diode is the simplest and most fundamental nonlinear circuit element. Just like resistor, it has two terminals. Unlike resistor, it has a nonlinear current- voltage characteristics. Its use in rectifiers is the most common application.

3. Physical Structure of Diode Diodes are formed by joining the N-type and P-type semiconductors

4. Diode is an electronic device which allows current to flow only in one direction The voltage applied to the semiconductor diode is referred to as bias voltage. Types of bias voltages: Forward Bias Reverse Bias

5. Forward Bias A forward biased diode conducts current in the forward direction A forward biased diode conducts current as long as a high external bias voltage with correct polarity is applied

6. Reverse Bias Extremely small current flows through the diode during reverse biasing. The minority carriers are forced towards the junction where they combine and support an extremely small current

7. Symbol and Characteristics for the Ideal Diode (a) diode circuit symbol; (b) i– v characteristic; (c) equivalent circuit in the reverse direction; (d) equivalent circuit in the forward direction.

8. I-V Characteristics of Practical Diode The Forward-Bias Region, determined by The Reverse-Bias Region, determined by The Breakdown Region, determined by

9. Formulas I-V characteristic equation: Exponential relationship, nonlinear. I s is called saturation current, strongly depends on temperature. or 2 V T is thermal voltage.

10. Types of Diodes PN Junction Diode Zener Diode Light Emitting Diode Photodiode Schottky Diodes PIN Diodes

11. Application of Diode Circuits Rectifier circuits  Half-wave rectifier  Full-wave rectifier Transformer with a center-tapped secondary winding Bridge rectifier Clippers Clampers … etc

12. Half-Wave Rectifier (a)Half-wave rectifier. (b)Equivalent circuit of the half-wave rectifier with the diode replaced with its battery-plus-resistance model.

13. Half-Wave Rectifier (c) Transfer characteristic of the rectifier circuit. (d) Input and output waveforms

14. Full-Wave Rectifier (a)circuit (b)transfer characteristic assuming a constant-voltage- drop model for the diodes

15. Full-Wave Rectifier (c) input and output waveforms.

16. The Bridge Rectifier (b) input and output waveforms (a) circuit

17. Clippers: A portion of an input signal waveform is “ Clipped” off

19. Clampers Clamp circuits are used to add adc component to an ac input waveform so that the positive (or negative) peaks are “clamped” to a specified voltage value.

21. Thank you