Nonlinear Applications of CCs - Current Conveyors: Variants, Applications and Hardware Implementations - page 238

a

C

I x1 B D

Y1

I x1

Y2

I z2

CCII 1 Z1

I R3

I R2

V 0 CCII 2 Z2

X1

X2

R 2 R3

I x2

R 5

R 1

R 4

A

R 6

b

V DD

V 0

V A

2

V D

2

V B

0V

1

V D V B

V D

1

V B

V SS

T 2 Time

T 1

t=T 1

t=t 0 t=T

Fig. 8.27 CCII-based oscillator proposed by Marcellis et al. (a) The circuit (b) voltage signals
behavior at circuit nodes (Adapted from [ 22 ] 2011 Wiley)

©

Using a straight forward but lengthy analysis [ 22 ], it is found that the oscillation
frequency of this circuit is given by:

1

h i

f 0 ¼ ð 8 : 40 Þ

ln 2 R 2 R 3 R 6 R 1 R 4 R 2 þ R 3

ð Þ

2 CR 2 þ ð R 3 Þ

R 1 R 4 R 2 þ ð R 3 Þ

The workability of this circuit has been verified in [ 22 ] using a CMOS CCII+
topology implemented in 0.35

m technology and has also been verified by
realizing CCII+ using AD844 biased with

μ

15 V DC power supplies. From the
experimental results it has been found that a frequency range from about 390 kHz to
780 mHz is feasible exhibiting a good linearity over a frequency range of about five
decades when the capacitor C was changed from 1 pF to 1 μ F.