Hardware Reference
In-Depth Information
R
eq
L
eq
I
1
I
2
V
1
V
2
C
p2
R
p2
R
p1
C
p1
Fig. 14.13 Equivalent circuit of FI in Fig.
14.12
with parasitic impedances (Adapted from [
31
]
©
2009 Elsevier)
14.12 Floating Simulator Employing DO-CCII and OTA
Sagbas et al. presented a FI function simulator [
29
] employing one DO-CCII, one
OTA and two grounded passive components. Their proposed structure can simulate
an
electronically-variable
positive/negative floating inductor or floating capacitor
or floating resistor by appropriate selection of the two admittances, without any
component-matching conditions.
The values of the simulated FI elements are
electronically-controllable
through
the biasing current of the OTA or through the grounded resistor or the capacitor.
Assuming ideal devices, a routine circuit analysis of the circuit of Fig.
14.14
yields the following short circuit admittance matrix:
g
m
y
1
y
2
1
1
½
¼
Y
ð
14
:
24
Þ
11
From the above equation, it is clear that one can simulate a FI, a capacitor or an
electronically-variable resistor by appropriate selection of the admittances y
1
and
y
2
.
The functionality of the simulated inductor of [
29
] was tested by employing this
in the design of a 5th order Chebyshev low pass filter designed for a cut-off
frequency of 1 MHz. The FI was realized with R
1
¼
1K
ʩ
,C
2
¼
17 pF and
g
m
¼
0.1 ms. The CMOS DOCCII therein (see Fig.
2
of [
29
]) was based onTSMC
0.35
m CMOS technology parameters. The simulation results of the filter with a
passive inductor and the simulated inductor of Fig.
14.14
demonstrated good
agreement.
μ
14.13 DO-CCCII Based Lossless Floating Inductance
Simulator Employing a Grounded-Capacitor
A number of authors have employed CCCII to realize a variety of grounded
and floating impedances such as [
12
,
13
,
18
,
24
,
36
,
48
]. Sagbas et al. in [
32
]
employed one DO-CCCII, one OTA and a grounded capacitor (Fig.
14.15
)to
realize a lossless grounded-capacitor FI simulator, without the requirement of any
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