First, Second and Higher Order Filter Design Using Current Conveyors - Current Conveyors: Variants, Applications and Hardware Implementations - page 150

a

C 2

Vin 2

R 3

x

+ z

V 2

Vin 3

x

V 1

−

y

z

R 2

y

CCII2

CCII1

R 1

C 1

Vin 1

b

C 1

R 1 R 2

CCII2

Vin 1

x

CCII1
x

− z

V 2

V 1

+ y

C 2

z

Vin 2

y

R 3

Vin 3

c

R 2

Vin 2

C 1

R 1

CCII2

Vin 1

x

CCII1
x

− z

V 2

V 1

+ y

z

C 2

y

R 3

Vin 3

Fig. 6.16 VM universal filters using CCIIs proposed by Liu and Lee [ 14 ]

If CCIIs of Fig. 6.16b are exchanged, another universal filter can also be
achieved.
The output voltage of the circuit of Fig. 6.17c is found to be:

V in 1 þ

s 2 C 1 C 2 R 2 R 3 ð sC 2 R 3 Þ V in 2 þ V in 3

R 1

V 1 ¼ ð 6 : 28 Þ

C 2 R 2 R 3

s 2 C 1 C 2 R 2 R 3 þ s þ 1

This filter structure is particularly attractive because grounded-capacitor realization
of LPF and BPF is available which is suitable for monolithic integrated circuit