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CXA1910Q
For the availability of this product, please contact the sales office.
Dolby B Type Noise Reduction System with Playback Equalizer
Description
The CXA1910Q is an IC designed for use in car
stereos. Functions include Dolby B type noise
reduction, playback equalizer amplifier and Music
sensor into a single chip.
Features
• Few external parts
• Forward/Reverse head switching
• Small package (40-pin QFP)
• Dolby B type noise reduction and playback
equalizer into a single chip
• Same pin configuration as Dolby B/C type noise
reduction system (CXA1911)
• Music sense level can be set by external
resistors/capacitors (2 modes).
• High-band cut filter frequency can be adjusted by
the external capacitance.
Absolute Maximum Ratings (Ta=25°C)
• Supply voltage VCC 12 V
• Operating temperature Topr –40 to +85 °C
• Storage temperature Tstg –65 to +150 °C
• Allowable power dissipation
Recommended Operating Condition
Supply voltage VCC 6.5 to 11 V
40 pin QFP (Plastic)
PD 430 mW
Applications
• Car stereos
• Stereo cassette deck players (playback only)
Structure
Bipolar silicon monolithic IC
∗ These ICs are 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 trade marks 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—
E93Z04-TE
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Block Diagram and Pin Configuration
CXA1910Q
PBTC1
PBFB1
PBRIN1
PBFIN1
PBGND
E IREF
PBFIN2
PBRIN2
PBFB2
PBTC2
NC
PBOUT1
GND
NC
TAPEIN1
VCT
NC1
LINEOUT1
NRSW
TC1
22 212324252627282930
NC
31
32
33
34
35
36
37
38
39
40
300k
F/R
F/R
300k
NR OFF
NR OFF
NR ON
AUX
TAPE
DR
NR
10dB
NR ON
NR
NR
IN
MS MODE
LPF
G1/G2
DET
20
TAPESW
19
DRSW
18
NRMODE
17
MSSW
16
MSMODE
15
G1 (FF)
14
G2 (NOR)
13
MSTC
12
MSOUT
11
1 2 3 4 5 6 7 8 9 10
Vcc
PBOUT2
NC
D IREF
TAPEIN2
MS LPF
LINEOUT2
NC2
TC2
MSGND
—2—
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CXA1910Q
Pin Description (Ta=25°C, VCC=8.0V, no signal)
Pin
Symbol
No. value
DC
Z (in) Equivalent circuit Description
1 PBOUT 2.1V —
30
32 PBFB 2.1V 300kΩ
39
33 PBIN 0V —
34
37
38
2VCC 8.0V —
10 MSGND 0.0V —
29 GND
35 PBGND
31 PBTC — —
40
Refer to Page 6.
PBEQ output
PBEQ feedback
PBEQ input
Power supply
Ground
PBEQ capacitance
Vcc
36 E IREF 1.25V —
11 MSOUT 0.0V for —
signal
detection;
5.0V for
no signal
detection
31
40
36
VDD=5V
11
147
42µ
147
147
30µ
20k
10µ
Vcc
1.25V
GND
Vcc
GND
Reference current setting
resistor pin
MS output
—3—
GND
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CXA1910Q
Pin
Symbol
No. value
DC
Z (in) Equivalent circuit Description
12 MSTC Approx. —
1.4V for
signal
detection;
5.0V for
no signal
detection
13 G2(NOR) 4.0V —
14 G1(FF)
3 TAPEIN 4.0V 40k
28
VDD=5V
13
14
12
147
147
1k
10µ
100k
15µ
50µ
Vcc
100µ
GND
Vcc
Connection of MS detection
Vcc
time constant
GND
MS feedback
TAPE input
6 D IREF 1.25V —
7 LINEOUT 4.0V —
24
28
3
147
40k
to VGS
GND
Vcc
Connection of reference
current setting resistor for
Dolby block
8k
200
200
50µ
1.25V
GND
Vcc
Line output
6
24
147
147
7
—4—
GND
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CXA1910Q
Pin
Symbol
No. value
DC
Z (in) Equivalent circuit Description
9 TC 0.3V —
22
15 MSMODE — —
17 NRMODE
18 DRSW
19 TAPESW
21 NRSW
22
Vcc
Time Constant pin for the level
×2
6µ
0.5µ
20k
9
147
600k
GND
Vcc
15
17
18
19
21
147
50µ
GND
detector
0.5µ
Refer to Page 6.
16 MSSW — —
25 VCT 4.0V —
4NC — —
8
20
23
26
27
5 MSLPF 4.0V 100k
25
16
147
100 k
147
30k
45k
30k
to VGS
50µ
50µ
GND
50µ
GND
VCC
Vcc
Vcc
Refer to Page 6.
VCC/2 output
No connection.
Capacitance connection for
adjusting the MS LPF time
constant.
5
147
64p
GND
—5—
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*
PBOUT, PBFB, PBIN equivalent circuit
CXA1910Q
Vcc
VREG
PBOUT
147
1
30
PBFB
32
39
PBIN
33
34
37
38
∗
Description for SW pins
10p300k
MSMODE - Switching of MS signal detection/blank detection
High: G1; Low: G2
NRSW - Switching of Dolby B type noise reduction ON/OFF
High: noise reduction ON; Low: noise reduction OFF
DRSW - Switching of tape direction
High: reverse; Low: forward
TAPESW - Switching of HIGH/NORMAL tape
High: NORMAL tape; Low: HIGH tape
NRMODE - Switching of noise reduction modes
High: noise reduction OFF; Low: Dolby B
MSSW - Switching of MS ON/OFF
High: MS ON; Low: MS OFF
500
500
600
GND
—6—