PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION 8 Semiconductors and Diodes Mc. Graw-Hill 1 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 10 i-v characteristic of semiconductor diode i. D Reverse breakdown region Reverse bias region Forward bias region _V Z V Complete i-v curve of a semiconductor diode Mc. Graw-Hill 2 GIORGIO RIZZONI v. D + v. D _ i. D © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 20 _ v + D + _ Mc. Graw-Hill vi = 155. 56 sin t i. D 3 GIORGIO RIZZONI RL + v. L _ © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Vi ( V ) Figure 8. 21 Ideal diode rectifier input and output voltages 0 0 0. 01 0. 02 0. 03 0. 04 0. 05 0. 06 0. 07 0. 08 0. 09 0. 1 VL ( V ) Time (s) 60 -Hz source voltage 0 0 0. 01 0. 02 0. 03 0. 04 0. 05 0. 06 Time (s) Rectified voltage Mc. Graw-Hill 4 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 29 Diode circuit for illustration of load-line analysis RT v. T i. D Mc. Graw-Hill 5 GIORGIO RIZZONI + v. D _ © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 30 Graphical solution of equations 8. 13 and 8. 14 i. D VT RT Q point ( I Q , V Q ) IQ VQ Mc. Graw-Hill 6 GIORGIO RIZZONI V T v. D © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 35 Piecewise linear diode model i. D Vs R Diode off circuit model r. D 1 r. D Q point 0 Mc. Graw-Hill 0 V Diode on circuit model V 7 GIORGIO RIZZONI Vs VD © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 42 Full-wave rectifier i 1 i. L 1: 2 N + _ v. S + Nv S _ RL + v. L _ + _ Nv S i 2 Mc. Graw-Hill 8 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 43 Full-wave rectifier current and voltage waveforms 10 Amps Volts 10 0 – 10 5 0. 005 0. 015 0. 025 0. 03 0 0. 005 0. 015 0. 025 0. 03 t (s) Source voltage 10 Amps Volts 10 5 0 t (s) Current i 1 0. 005 0. 015 0. 025 0. 03 5 0 0. 005 0. 015 0. 025 0. 03 t (s) Full-wave rectified load voltage Mc. Graw-Hill 9 GIORGIO RIZZONI t (s) Current i 2 © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 44 Full-wave bridge rectifier a D 2 D 1 c RL d v S ( t) +_ D 4 D 3 b Bridge rectifier a b AC in IC Rectifier c DC out d Corresponding IC package Mc. Graw-Hill 10 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 45 Operation of bridge rectifier a D 1 + v S (t ) _ D 4 c RL d i. L D 2 D 3 b During the positive half-cycle of v S (t), D 1 and D 3 are forward-biased and i L = v. S (t )/R L (ideal diodes). a + v S (t ) _ D 1 D 4 c RL d i. L D 2 D 3 b During the negative half-cycle of v S (t), D 2 and D 4 are forward-biased and i L = v S (t ) /R L (ideal diodes). Mc. Graw-Hill 11 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 49 DC power supply 110 v AC Line voltage + + _ v (t) AC _ Bridge rectifier + + Regulator v. R(t) _ V DC Load _ Filter Step-down transformer Mc. Graw-Hill 12 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 50 Zener diode model forward bias r. D + _ Mc. Graw-Hill V 13 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 51 Zener diode model for reverse bias r. Z _ + Mc. Graw-Hill VZ 14 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000

PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING THIRD EDITION Figure 8. 53 Complete model for Zener diode "Forward" branch "Reverse" branch r. D + V _ r. Z _ VZ + Complete model for Zener diode Mc. Graw-Hill Circuit symbol The Zener diode may be modeled as consisting of two parallel branches, representing forward and reverse operation. 15 GIORGIO RIZZONI © The Mc. Graw-Hill Companies, Inc. 2000