Hardware Reference
In-Depth Information
C 2
V in3
x
z
R 3
R 2
CCII+
y
V in2
V in1
x
CCII+
z
y
y
z
x
C 1
CCII-
R 1
V 0
Fig. 6.20 VM universal filter with three inputs single output using CCIIs+ proposed by Ozoguz
and Gunes [ 18 ]
Fig. 6.21 Universal active
VM filter with three inputs
and one output proposed by
Chang and Lee [ 19 ]
V in3
V in1
V in2
C 1
y
R 1
z
V 0
1
x
CCII-
CCII+
y
z
y
R 2
z
x
C 2
x
CCII+
R 3
The circuit shown in Fig. 6.22 has been proposed by the same authors [ 20 ] using
only two CCIIs and one voltage follower as a simplification to their proposition of
Fig. 6.21 . A little reflection into the role of the CCII
in the circuit of Fig. 6.21
shows that it is indeed redundant and can be deleted.
The expression of the output for the simplified circuit of Fig. 6.22 , however,
remains unchanged by this simplification and is, therefore, still given by Eq. ( 6.33 ).
With the CCIIs realized from AD844, good correspondence between theory and
experiments has been observed [ 19 ]. The circuit of Fig. 6.22 [ 20 ] has the advantage
of requiring one less CCII while providing all the features of its predecessor of
Fig. 6.21 [ 19 ]. Both the circuits are completely implementable with AD844 ICs.
6.2.3.4 Multi-Input-Multi-Output (MIMO)-Type VM Biquads
In this sub-section, we present a number of interesting MIMO-type VM biquads.
Chen Universal Biquad A MIMO-type universal filter configuration composed of
only one CCII
, two capacitors and three resistors was proposed by Chen [ 11 ],
 
Search WWH ::




Custom Search