Analog Filter Design Revisited: Circuit Configurations Using Newer Varieties of CCs - Current Conveyors: Variants, Applications and Hardware Implementations - page 375

a

R 1

C 2

C 1

I LP

I in

DVCC DVCC DVCC

z 2

y 1 y 2 z 1

y 1

z 1

1

2 3

I HP I BP

y 2 y 1

z 1 z 2 y 2 z 2

x x x

R 4

R 3

R 2

Electronic
Resistor

b

V A

M R1

I in

V in

M R2

V B

Fig. 12.12 (a) DVCC-based CM KHN-equivalent (b) realization of electronic resistor proposed
by Ibrahim et al. (Adapted from [ 15 ] © 2004 Elsevier GmbH)

output impedance nodes which is useful for easy cascading. A routine circuit
analysis of Fig. 12.12a gives the following CM transfer functions:

s 2 R R 2
Ds

C 1 R 2 R 3
Ds

R 1

s

I HP
I in ¼

I BP
I in ¼

ð 12 : 47 Þ

ðÞ ;

ðÞ

R 1
R 2 R 3 R 4 C 1 C 2 I LP

I in ¼

ð 12 : 48 Þ

Ds ðÞ

where

þ

1
C 1 R 2

R 1
C 1 C 2 R 2 R 3 R 4

s 2 Ds ðÞ¼ þ s ð 12 : 49 Þ

The filter parameters ˉ 0 and Q 0 are determined as:

r

R 1
C 1 C 2 R 3 R 2 R 4

r

R 1 R 2 C 1
R 3 R 4 C 2

ω 0 ¼ and Q 0 ¼ ð 12 : 50 Þ

Thus, the angular frequency ( ˉ 0 ) can be controlled without disturbing quality factor

(Q 0 ) by adjusting R 2 and R 4 simultaneously keeping (R 2 /R 4 ) constant. A notch filter