CXA1352AS Datasheet, PDF (9/17 Pages) Sony Corporation – 2-channel 5 Elements Graphic Equalizer IC

Fig. 2. Indicates frequency characteristics at boost and cut.
Response (dB)
Boost
CXA1352AS
0dB
• CXA1352AS system
VI
ωo _s
Q
H(s)= _{s2+ ωo s+ωo2}
Q
FIat
Cut
fO
Fig. 2.
fO= ¹
2π LC
Frequency (Hz)
R
Operational amplifier
VO
R
Z(s)
Z(s)
H(s)
Ic
Gm1
Ib
Gm2
Fig. 3.
The structure of the graphic equalizer used in this IC is shown on Fig. 3. This circuit performs boost and
cut controlled by 2 transconductance amplifiers that can vary the conversion coefficient through control
currents Ib, and Ic around ωo. (“ωo” is central frequency determined by Band Pass Filter.) Considering
output impedance Z (s) of Gm1, Gm2 we have
1
Z (s) =
H(s) • Gm1
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