Analog Filter Design Revisited: Circuit Configurations Using Newer Varieties of CCs - Current Conveyors: Variants, Applications and Hardware Implementations - page 426

R 3

x

z-

3
DOCC

y

z-

I 03

p

R 2

R 5

V 03

V 01

z- z-

1 2

y x

C 1 C 2

DOCC
z-

V 02

DOCC

I in

y

z+

x

I 01

I 02

R 1

y

z+
DOCC

4

R 4

z+

x

I 04

Fig. 12.55 Dual-mode biquad presented by Singh et al. [ 136 ]

I in 2 þ

C 1
R 4

I in 1
R 2 R 4

s 2 C 1 C 3 I in 3

N 2 s ðÞ¼ s

þ s 2 C 1 C 3

C 1
R 4 R 7

1
R 2 R 4 R 6

D r s ðÞ¼

R 5 þ

s ð 12 : 195 Þ

From the above equations, the various inverting and non-inverting mixed-mode
filter responses, with input voltage or current and output voltage or current, can be
obtained.

Singh- Singh-Senani biquad The filter configuration presented in Fig. 12.55 uses
four dual output CCs (DOCCs), five resistors and two grounded capacitors [ 136 ]. If
the current source I in deleted and V in applied at P, the circuit is essentially the same
VM biquad reported in [ 195 ], however, if P grounded and I in applied, the same
circuit yields the three output currents. Assuming ideal DOCCs, a routine circuit
analysis gives the following current transfer functions:

R 3 1 R 2 s R 1 s 2

C 1 R 1

I 01 R 5 I 02 R 5

and I 03

R 5

I in ¼

C 1 C 2 R 1 R 2

I in ¼ I in ¼

where

DðÞ ; DðÞ DðÞ

R 5
R 4 R 1 C 1

R 5
R 1 R 2 R 3 C 1 C 2

s 2

Ds ðÞ¼ þ s þ ð 12 : 196 Þ

By adding I 01 and I 03 a notch filter is realized and adding I 01 ,I 02 and I 03 anAPF can
be realized without any additional hardware requirement. The same circuit can also
function as mixed-mode biquad.