cxa2134q Sony Electronics, cxa2134q Datasheet - Page 25

• Manufacturer Part Number: cxa2134q
• Description: Us Audio Multiplexing Decoder
• Manufacturer: Sony Electronics

(COMPIN)
Description of Operation
The US audio multiplexing system possesses the base-band spectrum shown in Fig. 1.
13
MVCA
PEAK DEV
kHz
50
25
(SAP IN)
(ST IN)
STEREO LPF
25
22
SAP BPF
50 – 15kHz
Fig. 2. Overall block diagram (See Fig. 3 for the dbx-TV block)
(VCO 8f
L + R
PLL
NR SW
H
)
L-R (DSB)
CANCEL
25
SAP(FM)
PILOT
5
f
LOCK
H
DET
DET
INJ.
A
2f
f
f
HL
HL
SAP
DET
HL
DEEMPHASIS
AM-DSB-SC
90°
0°
0°
SAP LPF
Fig. 1. Base-band spectrum
LPF
MAIN LPF DE.EM
FIXED
SUB LPF
2f
NOISE
H
DET
I
DECODER
Fig 3. dbx-TV block
MODE
CONTROL
2
dbx-TV
PILOT
C BUS
DET
L-R
NR
DEEMPHASIS
(SAP OUT)
WIDEBAND
VARIABLE
SUBVCA
I
DECODER
2
C BUS
24
– 25 –
HPF
LPF
50
3f
H
(MAIN OUT)
I
DECODER
MODE
CONTROL
2
C BUS
(SUBOUT) (ST IN)
L – R
L + R
4.7µ
(VE OUT) (VCA IN)
21
9
RMS
(SAP IN)
DET
RMS
DET
29
4.7µ
4f
25
4.7µ
4.7µ
H
22
(MAIN IN)
30
8
NR SW
50 – 10kHz
dbx-TV NR
FM 10kHz
SAP
5f
VCA
H
A
B
BLOCK
dbx-TV
15
6f
to
MATRIX
f
TELEMETRY
H
H
= 15.734kHz
FM 3kHz
6.5f
B
CONTROL
MODE
MATRIX
H
3
f
(Lch)
(Rch)
CXA2134Q
to
TVSW