Second Generation Applications of Other Types of Current Conveyors in Realizing Synthetic Impedances - Current Conveyors: Variants, Applications and Hardware Implementations - page 472

V p

I p

Y 1

I z+

p

I−

w

−

z+ Y 2

x

z

V

OTA

DOCCII

I z− +

+

y

z− n

g m

I+

I n

V n

Fig. 14.14 Floating Simulator configuration proposed by Sagbas et al. (Adapted from [ 29 ] © 2009
Springer)

component-matching conditions. The simulated FI can be controlled electronically
through the bias current of the DO-CCCII or by varying the bias current of the
OTA. Assuming ideal DO-CCCII and OTA, the circuit analysis of the circuit of
Fig. 14.15 gives the following short circuit admittance matrix:

1

g m
sCR x

1

½ ¼ Y ð 14 : 25 Þ

11

where R x is the X-terminal parasitic resistance and is given by R x ¼

V T /2I 0 and
where V T is the thermal voltage and I 0 is the DC bias current of the DO-CCCII.
Thus, from the above equation, the value of simulated FI is given by:
L eq ¼ ( CV T / I B I 0 ) where I B is the bias current of the OTA.

Thus, it is seen that the inductance value can be controlled electronically through
either I B or I 0 . By grounding either of the ports, the presented configuration can
simulate an electronically adjusted grounded inductor.
The electronic-tunability of the proposed FI has been verified by simulating the
DO-CCCII and OTA by bipolar implementations based upon PR100N and
NR100N bipolar transistors from the transistor arrays ALA400 from AT&T with
circuits biased from 2.5 V DC supplies. The simulator was used in a 4th order LC

band pass filter whose SPICE simulation results were found to agree with theoret-
ical plots. The simulated inductor exhibited good frequency response from about
1 KHz till about 1 MHz.