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a
b
R
1
V
in
y
V
in
x
CCII+
z
V
0
CCII+
z
V
0
x
y
R
2
R
2
R
1
Fig. 5.3 Alternative realizations of CCII-based (a) Non-inverting (b) Inverting amplifier
Fig. 5.4 A simplified form
of the instrumentation
amplifier proposed by
Wilson [
67
]
CCII+
y
V
1
z
V
0
x
R
2
R
1
CCII+
x
z
y
V
2
resistors. Moreover, it has been claimed in [
142
] that high differential gain and
bandwidth can be achieved simultaneously.
For other works which have dealt with the design of constant bandwidth
instrumentation amplifiers using CCs see [
66
,
99
,
111
,
112
,
160
,
161
].
5.2.3 Constant-Bandwidth Current-Mode Operational
Amplifier
A constant BW current mode op-amp (COA) was proposed by Bruun [
143
]as
shown in Fig.
5.6
which requires three CCIIs.
When such a COA is configured as a finite gain current amplifier as shown in
Fig.
5.6b
, from a straight forward analysis, assuming Z
T
to be comprised of a
parasitic resistance R
T
in parallel with parasitic capacitance C
T
, it is found that the
maximum current gain is given by:
I
out
I
in
R
1
R
2
A
I
¼
1
þ
ð
5
:
10
Þ
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