Buck 变换器的 CCM 小信号传递函数
Buck 变换器的 CCM 小信号传递函数
(1)电路原理图
S
d
Vg
张兴柱 博士
L
iL
RL
io
D
RC
C
Vo
R
(2)CCM 小信号传递函数
)(ˆ
sGsv
o
vd
)(ˆ)(
sGsd
+
vg
)(ˆ)(
sv
g
=
Z
out
)(ˆ)(
si
s
o
)(ˆ
i
L
sGs
id
)(ˆ)(
sGsd
+
ig
=
)(ˆ)(
sGsv
g
)(ˆ)(
si
o
ii
+
)(
sG
vd
=
V
g
+
1
w
Qs
s
0
w
+
zc
2
s
+
1
2
w
o
=
G
vd
0
+
1
w
Qs
s
0
w
zc
+
2
s
+
1
2
w
o
)(
sG
vg
=
D
+
1
w
Qs
s
0
w
+
zc
2
s
+
1
2
w
o
=
G
vg
0
+
1
w
Qs
s
0
w
+
zc
2
s
+
1
2
w
o
Z
)(
s
out
=
R
L
+
1(
+
1
w
s
Qs
1)(
zL
+
w
0
s
2
+
s
)
zc
2
w
w
o
)(
sG
id
=
V
g
R
+
1
+
1
w
Qs
s
0
w
+
zp
2
s
2
w
o
=
G
id
0
+
1
w
Qs
s
0
w
+
zp
2
s
+
1
2
w
o
)(
sG
ig
=
D
R
+
1
+
1
w
Qs
s
0
w
+
zp
2
s
2
w
o
=
G
ig
0
+
1
w
Qs
s
0
w
+
zp
2
s
+
1
2
w
o
)(
sG
ii
=
+
1
w
Qs
s
0
w
+
zc
2
s
+
1
2
w
o
其中:
0 =w
zL =w
1
LC
RL
L
,
=
,
Q
w
1=w
CRC
zc
[
0
,
+
1
(
R
RL
1=w
RC
zp
L +
CR
)
C
]
1
·
-
·
·
·
·
·