Hardware Reference
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I ABC
I ABC1
I ABC2
I ABCn I n
x
z 1
x
x
z 1
x
z 1
z 1
R 1
R 2
R n
z 2
z 2
y
z 2
z 2
y
y
y
C 2
C 1
C n
I out
i 0
i 2
i n
i 1
y
z 1
y
z 1
z 1
y
I input
r 1
r n
r 2
z 2
z 2
z 2
x
x
x
i n
i 1
i 2
I ABC1
I ABC2
I ABCn
Fig. 12.42 Realization of the nth-order CM transfer function proposed by Abuelma ' atti and
Tasadduq [ 119 ]
12.2.9 Filter Design Using CFCCII
It has been conceptualized by some authors that if an additional current follower is
included in the CCII+ thereby making it a current follower CCII (CFCCII) then
such a modification becomes not only an useful artifice for synthesizing CM higher
order filters but can also lead to interesting CM universal biquads . A plus-type
current follower second generation CC (CFCCII p ) is characterized by the following
hybrid matrix:
2
3
2
3
2
3
I y
V x
I z
I 0
0000
1000
0100
0100
V y
I x
V z
V 0
4
5 ¼
4
5
4
5
ð
12
:
148
Þ
Figure 12.42 shows a translinear CFCCII p -based realization of nth-order current
transfer function using only grounded capacitors. The presented circuit configura-
tion is capable of supporting (n + 2) high impedance output currents simultaneously.
By appropriate connection of output currents, the circuit has the ability of
supporting a wide range of current transfer functions.
Abuelma ' atti-Tasadduq nth order transfer function realization using
CFCCII The method can be explained by considering a general form of nth
order transfer function as:
a 2 s 2
a n 1 s n 1
a n s n
I out
I input ¼
a 0 þ
a 1 s
þ
þ :::: þ
þ
ð
12
:
149
Þ
b 0 þ
b 1 s
þ
b 2 s 2
þ :::: þ
b n 1 s n 1
þ
b n s n
As per the methodology of [ 119 ], the active realization of this function is shown
in Fig. 12.42 .
 
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