PN Junction Devices

UNIT – I

Chapter – 1

b. PN Junction Devices

Syllabus

PN Junction diode – Structure, Operation and V-I characteristics, Diffusion and transisent capacictance – Recitfiers – Half wave and full wave rectifier – Display devices – LED, Laser diodes – Zener diode – Characterisitics – Zener reverse characteristics – Zener as regulator.

Contents

1.1     P-N Junction        1-2

1.2     Drift Current        1-2

1.3     Diffusion Current 1-2

1.4     Unbiased P-N Junction  1-3

1.5     The P-N Junction Diode 1-6

1.6     Forward Biasing of P-N Junction Diode     1-7

1.7     Reverse Biasing of P-N Junction Diode      1-9

1.8     Complete V-I Characteristics of a Diode ... 1-12

1.9     V-I Characteristics Equation of a Diode. ... 1-15

1.10   Derivation of V-I Characteristics of

P-N Junction Diode       1-17

1.11   Transition Capacitance (CT)   1-18

1.12   Diffusion Capacitance   1-20

1.13   Circuit Model of a Diode         1-22

1.14   Rectifiers    1-22

1.15   HalfWave Rectifier        1-23

1.16   Full Wave Rectifier        1-30

1.17   Bridge Rectifier    1-39

1.18   Comparison of Rectifier Circuits      1-43

1.19   LED  1-44

1.20   Seven Segment Display 1-46

1.21   Laser Diode          1-48

1.22   Zener Diode          1-49

1.23   Block Schematic of Regulated Power Supply      1-54

1.24   Zener Voltage Regulator          1-55

1.25   Two Marks Questions with Answers         1-59

1.26   University Questions with Answers

(Long Answered Questions)    1-65