CXA1917AM/AS
Dolby∗S type Noise Reduction Processor
Description
The CXA1917AM/AS is a bipolar IC designed for
use in the Dolby S type noise reduction system (NR).
An external operational amplifier is required to
configure the decoder. The stereo Dolby B-C-S type
NR combines use of a CXA1563M/S and two
CXA1917AM/AS ICs.
Features
• Considerable reduction in the number of external parts
(half compared to CXA1417S/Q)
• The same Dolby level as that of CXA1560 series ICs (–6dBm)
Structure
Bipolar silicon monolithic IC
30 pin SOP (Plastic)
30 pin SDIP (Plastic)
Absolute Maximum Ratings (Ta = 25°C)
• Supply voltage VCC to VEE 17 V
• Operating temperature Topr –20 to +75 °C
• Storage temperature Tstg –65 to +150 °C
• Allowable power dissipation PD (CXA1917AM) 600 mW
(CXA1917AS) 1200 mW
Recommended Operating Conditions
Supply voltage VCC 4.5 to 6.5 V
VEE –4.5 to –6.5 V
∗
This IC is available only to the licensees of Dolby Laboratories Licensing Corporation from whom licensing and applications
information may be obtained.
∗
"Dolby" and the double D symbols are trademarks of Dolby Laboratories Licensing Corporation.
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
– 1 –
E95Y15B74
C45
R28
10%
0.47µ
C44
24k
R47
0.1µ
2%
33
16
17
18
19
CC
V
TCF2L IREF
CXA1917AM/AS
2
1
VCC
GND
VREF
VEE
&
IREF
4
3
VCT
14 15
C48
0.1µ
VCT
10%
13
C46
10%
47
0.22µ
R48
12
R27
10k
C25
2%
39n
VCT
C30
R30
2.2n
8.2k
C42
2%
10%
0.22µ
C40
C34
R34
R31
C29
R45
47n
8.2n
1.5k
13k
470p
C38
1µ
47
2%
20
21
22
23
24
25
26
27
TCS2L TCF1L
FBOL TCS1L
SCBOL
SLDET SLICG
ANTSAT
FLVCR SLVCR
20k
FLDET FLICG
V to I
Conv H
17.5k
15k
SHICG
SHDET
SHVCRFHVCR
LFDET
FHDET FHICG
V to I
Conv H
LFVCR LFICG
11
10
9
8
7
6
5
4
R26
R19
33
R46
C41
C31
C27
18k 2%
R25 33
39k 2%
C7
C43
10%
0.47µ
0.1µ
8.2n
680p
10k 2%
R24
C24 39n
10%
C23 0.22µ
C20 22n
R16 39k 2%
C17 100n
100n
Tolerances of resistors are 5% without otherwise specified
Tolerances of film capacitors are 5% without otherwise specified
Tolerances of chemical capacitors are 20% without otherwise specified
Single Supply: Short GND to VEE and open VCT
Note) Split Supply: Short VCT to GND
VCT
C26 1µ
VCT
28
C14
R12
10k
C8
100n
22n
29
20k
MC4IN MC3IN MCBO HLSOUT ZHSL RECOUT SCINL
MC4
MC3DS
MC4
MC2
MC1
MC3DT
MC
MC3
MC1
30
VCT
R9
39k
5
RECOUT
Block Diagram and Pin Configuration (Encoder Unit)
GND
6
– 2 –
3
C16
VCT
0.22µ
2
C21
5.1k 2%
C19
2%
1.8n
R15
1.8n
R14 16k 2%
C11
INPUT
2.4k 2%
VCT
100n
7
HLSMP MCTC ZHSH ZL2 LFIN TCL1 TCL2 SCINH FBOH TCF1H TCF2H TCS2H TCS1H VCT VEE
1
R20
27k
R10
CXA1917AM/AS
Pin Description (DCV values are for Vcc = 6.0V and VEE = –6.0V.)
Pin No. Symbol DCV (V) Equivalent Circuit Description
VCC
1 HLSMP 0 HLS main path input
2 MCTC –3.9
3 ZHSH 0
1
VEE
VCC
1.5k
2
9.2k
2p
VEE
VCC
2.6k
3
Time constant for the
MC2
DC cut capacitance for
the HLS/HF/SB detector
4 ZL2 0
VEE
VCC
VCT
16k
4
HF/LF/FB pass band
rectifier input
GND
– 3 –
CXA1917AM/AS
Pin No. Symbol DCV (V) Equivalent Circuit Description
VCC
5
10.2k
5 LFIN 0 HLS/LF/FB-stage input
GND
VCC
1.5k
6 TCL1 –4.6
7 TCL2 –4.6
6
68k
VEE
VCC
7
300k
Primary time constant for
the HLS/LF/FB detector
Secondary time constant
for the HLS/LF/FB
detector
124k
VEE
VCC
500
8 SCINH 0 HLS/HF side chain input
8
500
VEE
– 4 –
CXA1917AM/AS
Pin No. Symbol DCV (V) Equivalent Circuit Description
VCC
9 FBOH 0 HLS/HF/FB VCR output
1.6k
9
22
5.1k
VCT
22 FBOL 0 LLS/HF/FB VCR output
GND
VCC
10 TCF1H 0
11 TCF2H –4.6
18 TCF2L –4.6
12 TCS2H –4.6
10
11
18
12
20
80k
364k
340k
22k
2k
Primary time constant for
the HLS/HF/FB detector
VEE
VCC
Secondary time constant
for the HLS/HF/FB
detector
Secondary time constant
for the LLS/HF/FB
detector
VEE
VCC
Secondary time constant
for the HLS/HF/SB
detector
20 TCS2L –4.6
46k
– 5 –
4k
Secondary time constant
for the LLS/FB/SB
detector
VEE