cxa1734s Sony Electronics, cxa1734s Datasheet - Page 17

• Manufacturer Part Number: cxa1734s
• Description: Us Audio Multiplexing Decoder
• Manufacturer: Sony Electronics

Description of Operation
(COMPIN)
The US audio multiplexing system possesses the base band spectrum shown in Fig. 1.
11
PEAK DEV
MVCA
kHz
50
25
14
19
STEREO LPF
50-15kHz
SAP BPF
Fig. 2. Overall block diagram (See Fig. 3 for the dbx-TV block)
L+R
(VCO 8f
NR SW
PLL
H
25
)
5
f
L-R (DSB)
CANCEL
H
SAP(FM)
PILOT
LOCK
DET
DET
INJ.
A
AM-DSB-SC
2f
f
f
DEEMPHASIS
HL
HL
SAP
DET
HL
90°
0°
0°
LPF
FIXED
SAP LPF
Fig. 1. Base band spectrum
MAIN LPF DE.EM
2f
SUB LPF
H
dbx-TV
NOISE
DET
Fig. 3. dbx-TV block
L-R
NR
I
DECODER
MODE
CONTROL
PILOT
2
C BUS
DET
DEEMPHASIS (VE OUT) (VCA IN)
(SAP OUT)
VARIABLE
WIDEBAND
SUBVCA
—17—
50
I
DECODER
HPF
3f
LPF
2
18
C BUS
H
(MAIN OUT)
I
DECODER
MODE
CONTROL
2
C BUS
(SUBOUT) (ST IN)
4.7µ
23
L+R
RMS
13
RMS
L-R
DET
DET
8
(SAP IN)
4f
4.7µ
H
4.7µ
19
4.7µ
14
24
(MAIN IN)
dbx-TV NR
FM 10kHz
50-10kHz
7
NR SW
SAP
5f
VCA
H
A
B
15
BLOCK
dbx-TV
6f
TO
MATRIX
f
H
TELEMETRY
H
=15.734kHz
FM 3kHz
6.5f
B
H
CONTROL
MODE
MATRIX
3
f
CXA1734S
(L-OUT)
(R-OUT)
28
29