Second Generation Controlled Current Conveyors (CCCII) and Their Applications - Current Conveyors: Variants, Applications and Hardware Implementations - page 271

Due to being a multiple-input-single-output (MISO)-type configuration, the
above mentioned KHN biquad suffers from the requirement of identical currents
to be applied in case of notch and all pass filters which will call for an additional
active element namely, a multiple output current follower (MOCF). Furthermore,
another drawback of the circuit is that additional realization conditions are needed
for designing both notch and all pass filters.
The above difficulties are easily over come in a design known as single-input-
multiple-output (SIMO)-type configuration and a number of such circuits using
CCCIIs have been evolved by various researchers. A circuit proposed by Wang
et al. [ 25 ] is particularly appealing and is shown here in Fig. 9.28 .
It is interesting to note that this circuit has only four CCCIIs (of course, three of
them have multiple output terminals) and five CM outputs each one of which is
available from a high output impedance terminal and each one realizing a specific
filter function as shown in the following.

K s 2 T 1 T 2
Ds

I 01
I in ¼

1
Ds

I 02
I in ¼

KsT 2
Ds

I 03
I in ¼

K ; ð 9 : 32 Þ

ðÞ ; ðÞ ; ðÞ

I 04
I in ¼

K s 2 T 1 T 2 þ

1 I 05

I in ¼

K s 2 T 1 T 2

sT 2 þ 1

ð 9 : 33 Þ

;

Ds ðÞ Ds ðÞ

Where

s 2 T 1 T 2 þ Ds ðÞ ¼ sT 2 K þ 1 ð 9 : 34 Þ

I B4

I B1

I in

Z+
Z+
Z+
Z+

Y

I 05

Y

Z−

4

I 04

Z−
Z+
Z+

1

X C 1

I 02

I 03 X

I B2

Z− Y

I B3 2

Z− C 2

X

X Z+

I01

3

Z

Y

Fig. 9.28 SIMO type CM universal biquad using CCCII proposed by Wang et al. (Adapted from
[ 25 ] © 2008, Birkhauser)