Prepara tus exámenes y mejora tus resultados gracias a la gran cantidad de recursos disponibles en Docsity
Gana puntos ayudando a otros estudiantes o consíguelos activando un Plan Premium
Prepara tus exámenes
Prepara tus exámenes y mejora tus resultados gracias a la gran cantidad de recursos disponibles en Docsity
Prepara tus exámenes con los documentos que comparten otros estudiantes como tú en Docsity
Encuentra los documentos específicos para los exámenes de tu universidad
Estudia con lecciones y exámenes resueltos basados en los programas académicos de las mejores universidades
Responde a preguntas de exámenes reales y pon a prueba tu preparación
Consigue puntos base para descargar
Gana puntos ayudando a otros estudiantes o consíguelos activando un Plan Premium
Comunidad
Pide ayuda a la comunidad y resuelve tus dudas de estudio
Ebooks gratuitos
Descarga nuestras guías gratuitas sobre técnicas de estudio, métodos para controlar la ansiedad y consejos para la tesis preparadas por los tutores de Docsity
Diodos, transistores, semiconductores.
Tipo: Apuntes
1 / 19
Esta página no es visible en la vista previa
¡No te pierdas las partes importantes!
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
Figure 4.24: (a)
A simple circuit used to illustrate the effect of a
filter capacitor.
(b)
input and output waveforms assuming an ideal
diode.
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
step #1:
source voltage is
biased, positive, diode is forward
capacitor charges.
step #2:
source voltage is
biased (blocking), reverse, diode is reverse-
capacitor
cannot discharge.
step #3:
source voltage is
biased, positive, diode is forward
capacitor charges
(maintains voltage).
Figure 4.24 (a)
A siŵple ĐirĐuit used to illustrate the effeĐt…
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
howThe textbook outlines
Laplace Transform
behavior below. may be used to define
output voltage for state #
output voltage for state # O
I
D
t
RC
O
peak
v
t
v
t
v
v
t
e
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
step #3:
Define output
voltage for state #1.
output voltage for state #
O
I
D
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
step #4:
Analyze circuit
state #2.
discharging. and capacitor isWhen diode is blocking
step #5:
Define
KVL and
for this circuit.
v O
Ri
L
i L = – i C
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
: take Laplace transform
: replace
with -
: define
differentially
: change sides
0
0
L
C
C C
O
O
L
O
O
C
O
O
i O
i
i i
O
dv
v
Ri
v
RC
dt
v
Ri
dv
v
R C
dt
dv
v
RC
dt
½
®
¾
¯
¿
§
·
¨
¸
©
¹
action
action
action
action
L
: take Laplace transform
tra
: seperate disalike / collect alike ter
nsform of
initial
1
( )
conditio
s n
m
0
0
0
O
O
dv dt
RCs
O
O
O
O
O
V
s
O
V
s
RC
sV
s
V
V
s
RCsV
s
RCV
ª
º
¬
¼
action
action
: eliminate
from both sides
: solve for
: pull out
C
(
1
1
)
R
1
0
1
0
1
1
0
1/
1
0
O
O
O
O
O
O
O
O
O
RC s
V
s
RC
s
R
V
O
C
s
V
s
V
RC
V
s
V
s
RC
V
s
V
s
RC
RCs V
s
RCV
RC
RC
§
·
¨
¸
©
¹
§
·
¨
¸
©
¹
action^ action
action
L
: solve : take inverse Laplace
0
t
RC
O
O
v
t
V
e
° ½
°
®
¾
°
°
¯
¿
action action
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
O
I
I
C
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
output voltage for state #2^ output voltage for state #
O
I
t
RC
O
peak
Figure 4.25:
Voltage and Current Waveforms in the Peak Rectifier
Circuit WITH
RC
>>
T
. The diode is assumed ideal.
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
The
diode conducts for a brief interval (
t ) near the peak
of the input sinusoid
and supplies the capacitor with
T discharge interval. The latter is approximately equal to charge equal to that lost during the much longer
.
Assuming an ideal diode, the diode
conduction begins at
time
t 1
(at which the input
v I equals the exponentially
decaying output
v
O ). Diode
conduction stops at time
t 2
shortly after the peak of
v
I (the exact value of
t 2 (^) is
determined by settling of
D ).
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
Q:
How is
ripple voltage
( V
r ) defined?
step #1:
Begin with
transient
response
of output duriŶg ͞ off
iŶterǀal.͟
step #2:
Note
T
is discharge
interval.
step #3:
Simplify using
assumption that
RC
>>
T.
step #4:
Solve for ripple voltage
V
r .
is discharge interval
because
,
we
:
can assume...
1
1
1
solve for
ripple voltage
(eq4.28)
)
(
RC T
r
t
RC
O
peak
peak
r
O
RC T
peak
r
peak
r
pea
T
RC
T
T
e
R
C
k
C
T
R^ V
v
t
V
e
V
V
v
T
V
V
V
e T
V
V
RC
!!
|
§
·
|
u
¨
¸
©
¹
§
·
|
¨
¸
©
¹
action
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
step #5:
Put expression in
terms of frequency
f
= 1/
Observe
that, as long as
r
peak
, the capacitor
current source ( discharges as constant
L ).
How is
conduction
interval
t ) defined?
“ee folloǁiŶg slides…
(eq4.29)
peak
pea
V
L^ R
k
r
fRC
fC
r
Oxford University Publishing
Microelectronic Circuits by Adel S. Sedra and Kenneth C. Smith (0195323033)
r
(eq4.29)
peak
pea
V
L^ R
k
r
fRC
fC
interval as assumed, conduction
will be small
when
(eq
r
peak
t
V
r
peak
V
t
^ D
