1
ECE201 Linear Circuit Analysis I
Lecture 32
Topic:
Impedance/admittance of 2-terminal devices
**
Impedance
≈
Resistance
Admittance
≈
Conductance
≈
:
not equivalent, but can be manipulated in the same manner.
1.
Z
in
( j
ω
)
=
V
in
I
in
Y
in
(j
ω
)
=
I
in
V
in
Z(j
ω
)
↑
Impedance
=
Re Z( j
ω
)
[
]
Resistance
1
2
4
3
4
+
jI
m
Z(j
ω
)
[
]
Reac tance
1
2
4
3
4
Y(j
ω
)
↑
Admit tance
=
Re Y(j
ω
)
[
]
Conduc tance
1
2
4
3
4
+
j I
m
Y(j
ω
)
[
]
Susceptance
1
2
4
3
4
2.
Devices in series and in parallel
Z
in
( j
ω
)
=
Z
1
(j
ω
)
+
Z
2
( j
ω
)
Y
in
(j
ω
)
=
1
Z
1
(j
ω
)
+
Z
2
(j
ω
)
I
in
+
V
in
–
Two
Terminal
Device
Z
in
(j
ω
) or Y
in
(j
ω
)
+
–
Z
in
(j
ω
)
or
Y
in
(j
ω
)
Z
1
(j
ω
)
Z
2
(j
ω
)

This
** preview**
has intentionally

**sections.**

*blurred***to view the full version.**

*Sign up*
2
3. Voltage and Current Division
V
1
=
Z
1
(j
ω
)
Z
1
(j
ω
)
+
Z
2
(j
ω
)
⋅
V
in
V
2
=
Z
2
(j
ω
)
Z
1
(j
ω
)
+
Z
2
(j
ω
)
⋅
V
in
I
1
=
Y
1
(j
ω
)
Y
1
(j
ω
)
+
Y
2
(j
ω
)
I
in
I
2
=
Y
2
(j
ω
)
Y
1
(j
ω
)
+
Y
2
(j
ω
)
I
in
+
–
Z
1
(j
ω
)
Z
2
(j
ω
)
+
V
1
–
+
–
V
2
V
in
Y
1
(j
ω
)
Y
2
(j
ω
)
I
in
→
↓ Ι
1
↓ Ι
2
Y
1
(j
ω
)
Y
2
(j
ω
)
Y
in
(j
ω
)
Z
in
(j
ω
)
Y
in
(j
ω
)
=
Y
1
(
)
+
Y
2
(
)
j
ω
j
ω
Z
in
(
)
=
Z
1
(
)Z
2
(
)
Z
1
(
)
+
Z
2
(
)
j
ω
j
ω
j
ω
j
ω
j
ω
where