Sinusoidal Oscillator Realizations Using Other Types of Current Conveyors - Current Conveyors: Variants, Applications and Hardware Implementations - page 439

Fig. 13.1 Single OFCC
based oscillator with dual
outputs proposed by Celma
and Martinez [ 1 ]

I 0

V 0

C 2

w

z

R C

R 2

OFCC

y x

R B

R A

R 1

C 1

13.2 A Dual-Mode Sinusoidal Oscillator Using a Single
Operational Floating Current Conveyor

An operational floating current conveyor (OFCC; as defined in Chap. 10 ), because
of being a four terminal building block, provides the flexibility of having a low
output impedance voltage output as well as a high output impedance current output.
This is immediately of interest when a circuit is needed for realizing a fixed
frequency oscillator which should be able to provide a voltage mode as well as
current mode output. One such circuit was advanced by Selma and Martinez in [ 1 ]
and is shown here in Fig. 13.1 .
The characteristic equation (CE) of the circuit of Fig. 13.1 is given by:

1
R 1 C 1 þ

1
R 2 C 2 þ

1
R 2 C 1

1
R 1 R 2 C 1 C 2 ¼

s 2

þ s ð 1 k 0 Þ þ 0 ð 13 : 1 Þ

(1+ R B where k 0 ¼

R A )
Thus, the condition of oscillation can be adjusted by varying R A or R B . It is seen
that both voltage and current outputs are available from this circuit.
The aspect of determining the limit cycle stability in CM oscillators using OFC
has been investigated by Celma and Martinez in [ 2 ].
The oscillator of Fig. 13.1 was practically tested and its operation verified by
realizing the OFC using two CCIIs in the IC CCII01 from LTP Electronics.

13.3 ICCII-Based Grounded-Capacitor (GC) SRCO

Several authors have described new oscillator topologies using ICCII, for example,
[ 26 , 27 , 33 , 34 , 42 ]. An exemplary ICCII-based oscillator has been shown in
Fig. 13.2 which employs a single ICCII, two grounded capacitors and three resistors
and was proposed by Horng, Wang and Yang in [ 42 ].