1. Diode 1

2. Diode applications 2

3. Diode symbols 3

4. I-V characteristic 4

5. Testing diode 5

6. Temperature effects 6

7. Diode datasheet 7

8. Ideal diode 8

9. Ideal half wave rectifier 9

10. Solar Cell (photovoltaic cell) 10

11. Light Emitting Diode (LED) 11

12. Infrared LED (IR LED) 12

13. Photodiode 13

14. IR LED + Photodiode application 14

15. 15 Schottky diode I-V characteristics  Schottky diode is a metal-semiconductor (MS) diode  Historically, Schottky diodes are the oldest diodes  MS diode electrostatics and the general shape of the MS diode I-V characteristics are similar to p + n diodes, but the details of current flow are different.  Dominant currents in a p + n diode  arise from recombination in the depletion layer under small forward bias.  arise from hole injection from p + side under larger forward bias.  Dominant currents in a MS Schottky diodes  Electron injection from the semiconductor to the metal.

16. Zener diode 16 What is a Zener Diode?: A Zener diode is a special case of ordinary semiconductor silicondiode. Specifically, the Zener displays the following property: The direction of current is from positive to negative and it blocks current in the minus to plus direction (Reversed Bias). See sketch for Zener diode symbol and picture of markings on a part itself. If a positive voltage is applied to the anode terminal of a Zener diode and a negative voltage is applied to cathode terminal, the Zener diode will behave as an ordinary semiconductor diode. However, when a positive voltage is applied to the negative, the Zener diode will breakdown when it is reversed biased by a voltage greater than the breakdown voltage. As a result a Zener voltage (Vz) will appear across the diode terminals, with its cathode being positive and the anode being negative.See Figure below for pictorial and associated symbol:diode See example below for more information In the preceding figure which reflects a zener diode acting as a zener voltage regulator across load resistor R2.zener voltage regulator

17. Zener diode 17

18. Rectifier Circuits  Transformers  Step Down/Up  Electrical isolation => Minimize risk of Electrical shock  Rectifier  converts sinusoidal input into uni-polar output – pulsating dc with nonzero average components  Unsuitable for equipments  Needs filtering and smoothing

19.  Filter  Smoothes out pulsating dc but still some time-dependent components-(ripple) remain in the output  Voltage Regulation  Reduces ripples  Stabilizes magnitude of dc output against variation in load current  Regulation by Zener Diode or Voltage regulator I.C Rectifier Circuits