Hardware Reference
In-Depth Information
a
b
R
C
I
in
y
I
in
y
z
V
in
V
in
CCI
z
CCI
R
R
x
x
C
R
2
Y
in
R
Y
in
R
2
Fig. 5.21 Lossless grounded inductors using CCI
The circuit can realize a lossless grounded inductor or a lossy inductance in the
form of series RL or parallel RL subject to the fulfillment of appropriate conditions.
The input impedance of the circuit is given by:
R
1
R
2
þ
R
2
R
3
þ
ð
R
4
Þ
R
1
R
4
sC
1
R
1
R
2
R
4
Z
in
¼
ð
5
:
27
Þ
sC
2
R
2
R
3
f
ð
Þ
R
1
R
4
g
R
4
Subject to fulfillment to the following conditions:
2
R
2
R
3
¼
R
1
R
4
and R
2
R
1
þ
ð
R
3
þ
R
4
Þ
¼
R
1
R
4
ð
:
Þ
5
28
the input impedance becomes purely inductive and is given by:
sCR
1
R
2
R
4
R
4
Z
in
¼
¼
sCR
1
R
2
ð
5
:
29
Þ
Recently, Arslan, Cam and Cicekoglu in [
105
] have presented two new lossless
grounded inductance simulators using a single first generation current conveyor
(CCI). The circuits although employ a floating capacitor, like that in Soliman
s
'
circuit [
9
], but require one less resistor. These circuits are shown in Fig.
5.21
.
With the component values shown, both the circuits realize Z
in
¼
sCR
2
/3. The
practical workability of these circuits has been successfully demonstrated [
105
]in
the realization of a third order high pass Butterworth filter with a CMOS CCI for cut
off frequency of the order of 106 KHz.
5.3.3 Single CCII-Based Low-Component-Count Grounded
Impedance Simulators
As compared to lossless grounded inductance, a lossy inductor can often be
simulated with a canonical number of components typically using only one CC,
two resistors and a capacitor. A number of such circuits have been proposed in
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