Sony STR-313L - Integrated Circuits (ICs); CX168 Main Function; CX178 Main Function; Photo Interrupter (IC401, 402)

“STR-313L
1C201 (CX168), 1C202 (CX178) <General>
@ Muting Gate
Regulator
These two ICs form a system. Both of them are
Muting Canceler Circuit
e
bipolar-linear-ICs. CX168 integrates 343 elements and e
CX178 integrates 260 elements. They include many @ Pop-noise Canceler
functions and are improved upon the degree of inte- @ Hysteresis Circuit
gration now available as a linear-ICs for tuner use.
They have high performance in FM reception and
form a muting system having an FM muting attenua-
tion of 90dB. In addition, because a muting circuit is
newly employed in the AM circuit not only is there
' high performance in FM reception but AM station The terminals () and (2) of the photo interrupter
| operate as the light emitting diode. On the other
' signal can be received with fine tone quality and sen- pg ah cats
| sitivity as with FM broadcasting station. As an addi- and, the terminals (3) and (4) operate as the photo
detector. When the photo detector receives the light
tional
function,
they
operate
for
FM/AM
continuous
Pace
: :
station selection, FM/AM signal-strength meter out- ON in Fig. a, the terminal Derwcen senminals (3)
put, FM/AM muting output switching and enforced and (4) is a low-impedance. When light is intercepted
AGC
at
FM
reception.
by
the
marker,
as
shown
in
Fig.
4,
it
becomes
high-
impedance.
Photo Interrupter (1C401, 402)
CX168 Main Function When the photo detector receives the light | When light is intercepted
photo interrupter (1C401, 402)
photo detector
photo detector.
<FM>
IF Amplifier
Quadrature
detector
aoe
Signal-strength
Meter
Output
LC
aaa
ee
=|
Muting
Signal Output
light
emitting
-—
AFC
Output
for
Converter
diode
Side
view
Back
view
Multipath
Signal
Output
light
emitting
diode
Bandpass
Control
Circuit
Fig.
3
Fig.
4
p M>
RF Attenuator
Mixer
Oscillator
IF Amplifier and AGC
AM Detector
Signal-Strength Meter Output
Signal Generator for AM Muting
<General>
® Regulator
@ FM/AM Switching
® Regulator Output
CX178 Main Function
<FM Stereo Demodulator>
@ FM Stereo Demodulator
Phase Detector
Stereo Indicating Circuit
vco
VCO ON/OFF Circuit