CXA2094 Sony Corporation, CXA2094 Datasheet - Page 16

• Manufacturer Part Number: CXA2094
• Description: US Audio Multiplexing Decoder
• Manufacturer: Sony Corporation

(COMPIN)
Description of Operation
The US audio multiplexing system possesses the base band spectrum shown in Fig. 1.
12
MVCA
PEAK DEV
kHz
50
25
STEREO LPF
(SAP IN)
(ST IN)
23
27
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
SAP(FM)
25
PILOT
LOCK
5
f
DET
INJ.
DET
H
A
2f
f
f
HL
HL
SAP
DET
HL
AM-DSB-SC
90°
0°
0°
DEEMPHASIS
SAP LPF
MAIN LPF DE.EM
Fig. 1. Base band spectrum
SUB LPF
FIXED
LPF
2f
NOISE
DET
H
I C BUS
DECODER
MODE
CONTROL
Fig 3. dbx-TV block
PILOT
2
dbx-TV
DET
L-R
NR
(SAP OUT)
WIDEBAND
DEEMPHASIS
SUBVCA
I C BUS
DECODER
2
25
VARIABLE
50
– 16 –
3f
HPF
LPF
H
(MAIN OUT)
I
DECODER
MODE
CONTROL
2
C BUS
(SUBOUT) (ST IN)
4.7µ
L – R
L + R
22
4
(VE OUT) (VCA IN)
(SAP IN)
34
RMS
DET
RMS
DET
4.7µ
4f
27
4.7µ
H
4.7µ
23
LPF
(MAIN IN)
35
3
NR SW
50 – 10kHz
dbx-TV NR
FM 10kHz
(SOUT)
SAP
5f
38
H
VCA
A
4.7µ
(ESAPIN)
BLOCK
dbx-TV
39
B
15
6f
f
to
MATRIX
TELEMETRY
H
H
= 15.734kHz
FM 3kHz
6.5f
B
CONTROL
MODE
MATRIX
H
3
f
(Lch)
(Rch)
CXA2094Q
(TVOUT-S)
to
TVSW
40