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8. Semiconductors and Diodes. i. D. Reverse. breakdown. region. Reverse. bias. region. Forward. bias. region. _. V. Z. V. v. D. i. Complete. i. -. v. curve of a. D. +. semiconductor diode. v. D. _. Figure 8.10 i-v characteristic of semiconductor diode. _. v. +.
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8 Semiconductors and Diodes
i D Reverse breakdown region Reverse bias region Forward bias region _ V Z V v D i Complete i - v curve of a D + semiconductor diode v D _ Figure 8.10 i-v characteristic of semiconductor diode
_ v + D + + R v v = 155.56 sin t _ L L i _ i D Figure 8.20
Vi ( V ) 0 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 Time (s) 60-Hz source voltage VL ( V ) 0 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1 Time (s) Rectified voltage Figure 8.21 Ideal diode rectifier input and output voltages
R T + v v T D _ i D Figure 8.29 Diode circuit for illustration of load-line analysis
i D V T R T Q point ( I , V ) Q Q I Q V V v Q T D Figure 8.30 Graphical solution of equations 8.13 and 8.14
i D Diode off V circuit model s R r D 1 V r D Diode on Q point circuit model 0 0 V V V s D Figure 8.35 Piecewise linear diode model
i i 1 L 1 : 2 N + + R v L L Nv _ S _ + v _ S + Nv S _ i 2 Figure 8.42 Full-wave rectifier
10 10 5 0 Amps Volts – 10 0.005 0.01 0.015 0.02 0.025 0.03 0 0.005 0.01 0.015 0.02 0.025 0.03 (s) t (s) t Source voltage Current i 1 10 10 5 Volts 5 Amps 0 0.005 0.01 0.015 0.02 0.025 0.03 0 0.005 0.01 0.015 0.02 0.025 0.03 t (s) (s) t i Full-wave rectified load voltage Current 2 Figure 8.43 Full-wave rectifier current and voltage waveforms
a D D 2 1 R c L d + v ( t ) _ S D 4 D 3 b Bridge rectifier a c IC DC out AC in Rectifier b d Corresponding IC package Figure 8.44 Full-wave bridge rectifier
a D D + 2 1 R c L d v ( t ) S _ i L D D 3 4 b During the positive half-cycle of v ( t ) , D and D are forward-biased S 1 3 and i v t ( ) / (ideal diodes). = R L S L a D D 2 + 1 R c d L v ( t ) S _ i L D D 4 3 b During the negative half-cycle of v are forward-biased ( t ) , D and D S 2 4 and i = v ( t ) (ideal diodes). / R L S L Figure 8.45 Operation of bridge rectifier
110 v + AC + + Bridge + Line rectifier v ( t ) v ( t ) Regulator Load V _ voltage DC AC R _ _ _ Filter Step-down transformer Figure 8.49 DC power supply
r D + V _ Figure 8.50 Zener diode model for forward bias
r Z _ V Z + Figure 8.51 Zener diode model for reverse bias
"Forward" "Reverse" branch branch r r D Z + _ V V Z _ + The Zener diode may be modeled as consisting of two parallel branches, representing Circuit Complete model symbol forward and reverse operation. for Zener diode Figure 8.53 Complete model for Zener diode