SONY CXA1911

CXA1911Q
Dolby B/C Type Noise Reduction System with Playback Equalizer
For the availability of this product, please contact the sales office.
Description
The CXA1911Q is an IC designed for use in car
stereo cassette decks. Functions include Dolby B/C
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/C type noise reduction and playback
equalizer into a single chip
• Same pin configuration as Dolby B type noise
reduction system (CXA1910Q)
• Music sense level can be set by external
resistors/capacitors (2 modes).
• High-band cut filter frequency can be adjusted by
the external capacitance.
40 pin QFP (Plastic)
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
PD
430
mW
Recommended Operating Conditions
• Supply voltage
VCC
7.8 to 11
V
Applications
• Car stereo cassette decks
• Cassette decks (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—
E93Y13-TE
CXA1911Q
29
28
26
25
24
NRSW
TCH1
TCL1
LINEOUT1
VCT
NC
27
23
22
21
31
20
30
NC
TAPEIN1
GND
PBOUT1
Block Diagram
NC
19
32
PBTC1
PBFB1
TAPESW
33
300k
IN
PBRIN1
F/R
17
34
18
NR
DRSW
NRMODE
PBFIN1
16
35
TA PE
MSSW
DR
36
PBFIN2
MODE
A MS
NR
14
37
E IREF
F/R
10dB
LPF
13
300k
38
15
PBGND
PBRIN2
MSMODE
G1 (FF)
G2 (NOR)
G1/G2
DET
12
39
NR
MSTC
40
—2—
9
MSGND
10
TCH2
8
TCL2
7
LINEOUT2
6
D IREF
5
MSLPF
4
NC
3
TAPEIN2
2
Vcc
1
PBOUT2
PBTC2
11
PBFB2
MSOUT
CXA1911Q
Pin Description
1
30
32
39
33
34
37
38
2
3
28
Symbol
DC
value
Z (in)
PBOUT
2.1V
—
PBFB
2.1V
300kΩ
PBIN
0V
—
VCC
TAPEIN
8.0V
4.0V
—
40kΩ
Equivalent circuit
Refer to Page 7.
PBEQ output
PBEQ feedback
PBEQ input
Power supply
TAPE input
3
147
28
VGS
4
20
26
27
5
NC
—
—
MSLPF
4.0
100kΩ
Description
40k
Pin
No.
(Ta=25°C, VCC=8.0V, no signal)
12µA
No connection
VCC
100k
5
147
64p
GND
—3—
Adjustment of MS LPF
frequency
CXA1911Q
Pin
No.
Symbol
DC
value
Z (in)
6
D IREF
1.25V
—
Equivalent circuit
Description
Connection of reference
current setting resistor for
Dolby block
6
50k
147
7 LINEOUT
24
4.0V
—
Line output
VCC
147
200
7
200
24
GND
TCL
0.3V
—
Time Constant pin for the LLS
13.5k
8
23
23
TCH
0.3V
147
—
Time Constant pin for the HLS
36k
9
22
480k
8
22
10
29
35
MSGND
GND
PBGND
0.0V
330k
9
147
—
Ground
—4—
CXA1911Q
Pin
No.
Symbol
11
MSOUT
DC
value
0.2 V
Z (in)
—
Equivalent circuit
VDD=5V
Description
MS output
VCC
for signal
detection;
147
5.0 V for
11
no signal
20k
detection
GND
12
MSTC
Approx.
—
VDD=5V
Vcc
1.4 V for
signal
Connection of MS detection time
constant
50µ
147
12
detection;
1k
5.0 V for
no signal
detection
GND
13
14
G2(NOR)
G1(FF)
4.0V
—
MS feedback
VCC
10µ
13
147
100k
14
100µ
GND
15 MSMODE
18
—
—
15
DRSW
50µ
18
50µ
19
19
TAPESW
21
NRSW
16
MSSW
147
21
MSMODE MS gain selector
G1 when high, G2 when low
DRSW
Head selector
Reverse when high, Forwards
when low
TAPESW Equalizer selector
120µs when high, 70µs when
low
NRSW
—
—
VCC
50µ
50µ
147
16
GND
—5—
NR ON/OFF selector
MS on/off selector
MS on when high, MS off when
low
CXA1911Q
Pin
No.
Symbol
17 NRMODE
DC
value
Z (in)
—
—
Equivalent circuit
Description
Noise reduction selector
C when high, B when low
50µ
50µ
17
50k
147
2.5V
VCT
4.0V
—
VCC/2 output
30k
25
Q3
to VGS
147
25
30k
45k
31
40
PBTC
—
—
VCC
PBEQ capacitance
147
31
40
42µ
30µ
GND
36
E IREF
1.25V
—
VCC
147
1.25V
36
10µ
GND
—6—
Connection of reference current
setting resistor for PBEQ block
CXA1911Q
• PBOUT, PBFB, PBIN equivalent circuit
Vcc
VREG
PBOUT
147
1
30
PBFB
300k
10p
32
39
PBIN
600
33
34
GND
37
38
Electrical Characteristics (Ta=25°C, VCC=8.0 V, RL: output load resistance, Rg: head equivalent impedance;
unless otherwise specified, 120 µs, FWD mode, NR OFF, MS OFF)
Item
Operating voltage
Symbol
Measurement conditions
(input pin, input level frequency etc.)
Vopr
Min.
Typ. Max. Unit
7.8
8.0
11.0
V
21.9
25.5
mA
ICC
No signal
18.5
TAPE IN input sensitivity
VTIN
LINE OUT=0dB 1kHz
–32.0 –30.0 –28.0 dBm
NR B decode boost 1
BP1
500Hz, LINE OUT –25dB, NR B, TAPE IN
1.4
3.4
4.4
NR B decode boost 2
BP2
2kHz, LINE OUT –25dB, NR B, TAPE IN
5.5
6.0
8.5
NR B decode boost 3
BP3
5kHz, LINE OUT –25dB, NR B, TAPE IN
3.9
5.1
6.9
NR B decode boost 4
BP4
10kHz, LINE OUT –40dB, NR B, TAPE IN
9.7
10.2
11.9
NR B decode boost 5
BP5
10kHz, LINE OUT 0dB, NR B, TAPE IN
–1.1
0
1.9
NR C decode boost 1
CP1
500Hz, LINE OUT –60dB, NR C, TAPE IN
14.2
16.5
18.2
NR C decode boost 2
CP2
500Hz, LINE OUT –25dB, NR C, TAPE IN
7.2
9.8
11.2
NR C decode boost 3
CP3
2kHz, LINE OUT –60dB, NR C, TAPE IN
18.7
20.9
22.7
NR C decode boost 4
CP4
2kHz, LINE OUT –25dB, NR C, TAPE IN
5.4
7.3
9.4
NR C decode boost 5
CP5
5kHz, LINE OUT –25dB, NR C, TAPE IN
3.5
5.7
7.5
NR C decode boost 6
CP6
10kHz, LINE OUT 0dB NR C, TAPEIN
–5.5
–3.9
–1.5
Current consumption
Dolby block (Dolby level -6 dBm=0 dB)
—7—
dB
dB
CXA1911Q
Electrical Characteristics
Item
Symbol
Measurement conditions
(input pin, input level frequency etc.)
Min.
Typ. Max. Unit
TAPE IN total harmonic distortion 1
THD1
TAPE IN –20dBm 1kHz R1=2.7k
—
0.01
0.2
TAPE IN total harmonic distortion 2
THD2
TAPE IN –20dBm 1kHz NR B R1=2.7k
—
0.04
0.2
TAPE IN total harmonic distortion 3
THD3
TAPE IN –20dBm 1kHz NR C R1=2.7k
—
0.07
0.3
Decode S/N ratio
SN1
No signal NR B CCIR/ARM filter
77.0
84.0
—
SN2
No signal NR C CCIR/ARM filter
80.0
82.0
—
%
dB
Signal handling
VSH1
TAPE IN 1kHz RL=2.7KΩ THD=1%
13.5
14.4
—
Cross talk TAPE IN 1 ch → 2 ch
CT3
TAPE IN –24dBm 1kHz
—
–91
–55
LINE OUT offset voltage
VOS1
No signal
3.9
4.0
4.1
V
Level at PB IN to LINE OUT, LINE OUT
—
70
100
mV
B/C Switching noise
VBOTU
dB
Playback equalizer amplifier block
120 µs FWD frequency response
70 µs FWD frequency response
PBREF PB F IN 315Hz –70dBm VPBO=0dB
–27.0 –25.5 –23.0 dBm
F120F
PB F IN 2.7 kHz -58.5 dBm for 315 Hz
–1.5
–0.8
1.5
F70F
PB F IN 4.5 kHz -53.8 dBm for 315 Hz
–1.5
–0.0
1.5
PB R IN 315 Hz -70 dBm for 315 Hz
–1.0
–0.3
1.0
–10.0 –3.0
—
dBm
F120R
dB
dB
Signal handling
VSH2
PB F IN 1kHz THD=1% RL=2.7kΩ
Total harmonic distortion
THD6
PB F IN 1kHz –52dBm RL=2.7kΩ
—
0.11
0.5
%
S/N ratio
SN3
No signal "A" weighting filter ON
57.0
61.1
—
dB
Output offset voltage
VOS2
No signal Rg=2.2 kΩ
1.55
1.95
2.35
V
Cross talk between channels
CT4
—
–80.5
–70
Cross talk between RVS and FWD
CT5
—
–77.7
–65
TAPE IN 1kHz –42dBm
Interval detection between tracks (MUSIC SENSOR) block
TAPE IN 5 kHz AMS ON (G1 mode)
VMS1
Signal detection level 1
External constant 10 kΩ, 0.015 µF
Signal detection level 2
VMS2
MS output leak current
IOH
MS output saturation voltage
VOL
TAPE IN 5 kHz AMS ON (G2 mode)
External constant 1 kΩ, 1.5 µF
TAPE IN 5 kHz -10 dBm, 5 V applied to
AMSOUT
TAPE IN 5 kHz -30 dBm, 1 mA applied to
AMSOUT
dB
–43.0 –39.0 –35.0
dBm
–62.5 –58.5 –54.5
—
0.0
1.0
µA
—
0.3
1.0
V
0.0
—
0.8
Logic voltage
VIL
2-value input
VIH
NRSW, TAPESW, DRSW, NRMODE,
MSSW, MSMODE
V
2.5
—
VCC
1.0
3.0
—
—
—
3.4
Boost charge circuit block
PBFB boost charge current
ICRG
Boost charge ON VCT level
VCRG1
Boost charge OFF VCT level
VCRG2
No signal, 3.4 V applied to VCT and 1.8 V
to PBFB
No signal, VCT level when boost charge
ON
No signal, VCT level when boost charge
OFF
—8—
mA
V
3.6
—
—
GND
R1
GND
DC Ammeter A
Vcc
Power
Supply
R2 1.2k
1.2k
19.2k
19.2k
19.2k
19.2k
R7
R3 S4
R8
R4 S3
R9
R5 S2
R6 S1
R13
R14
2.7k
2.2k
C6
4.7µ
2.2k
4.7µ
C3
C4
2.2k
4.7µ
2.2k
4.7µ
C5
C2
R12 C1
R11
S6
15k
R15
10n
10n
33µ 270
C8
270 C7 33µ
2.7k
31
32
33
34
35
R10
27
26
25
22
NC
1
PBTC2
PBFB2
PBRIN2
PBFIN2
E IREF
PBGND
PBFIN1
2
3
4
5
8
9
10
MSOUT
MSTC
G2
G1
MSMODE
MSSW
NRMODE
DRSW
21
PBRIN1
7
23
TAPESW
6
24
NRSW
PBFB1
PBTC1
C9
36
G1
PBOUT2
10µ
C11
10µ
R16
Audio
SG
1µ
138.5k
37
28
C16
38
29
20k
C19
39
R17
GND
C10
1µ
PBOUT1
R19
5.1k
S7
C13
Vcc
138.5k
1µ
TAPEIN1
TAPEIN2
30
NC
NC
C18
R28
150P
S8 C12
5.1k
R18
R29
2.2µ
2.7k C21
S14
S5
NC
MSLPF
C24
C23 68n
40
LINEOUT1
LINEOUT2
10µ
VCT
D IREF
S13
R30
C29 22µ
C22
2.7k
68n
TCL1
TCL2
0.1µ
TCH1
0.1µ
TCH2
MSGND
20
19
18
17
16
C27
1k 1.5µ
10k 0.015µ
C26
R31
R32
1
5
14
13
S15
R45
C25
100k
12
11
V7
V5
V4
V3
V2
V1
0.1µ
R33
—9—
1MEG
10k
100
R40
S22
S23
S24
S25
10k
10k
100
100
R36
R35
R34
S21
S20
R37
100
10K
R38
R39
S17
S18
100
R42
R41
S19
S16
10k
R43
DIN Audio
"A" WTG
Oscillo
-scope
Distortion
Analyzer
AC
Voltmeter
CCIR
S32
S31
S30
S29
S28
OFF : 0dB
ON : 30dB
GND
1kHz BPF
R44
GND
Amp
0dB or 30dB
DC
Voltmeter
50k
S26
Electrical Characteristics Measurement Circuit
CXA1911Q
CXA1911Q
Operating modes (TAPESW, DRSW, NRSW, MSSW, MODESW, NRMODE)
The CXA1911Q has an NR switch (NRSW), NR mode switch (NRMODE), equalizer switch (TAPESW), head
switch (DRSW), MS switch (MSSW), and MS gain switch (MSMODE).
The operating modes for each switch are shown in the following table.
SW
NRSW
NRMODE
TAPESW
DRSW
MSSW
MSMODE
Function for Low input
NR OFF
DOLBY B
70µS
PB FWD
MS OFF
G2 MODE
Function for High input
NR (B/C) ON
DOLBY C
120µs
PB RVS
MS ON
G1 MODE
Click noise can be reduced by the external CR time constant for NRSW switching.
—10—
CXA1911Q
Description of Operation
1. Signal route
PBFB PBTC
PBOUT
Dolby level
(–6dBm)
LINEOUT
TAPEIN
Op1
Op2
4dB
NR
20dB
NR ON
NR OFF
20dB
PBIN
F
R
Fig. 1
Op1 and Op2 are operational amplifiers.
Op1 composes the playback equalizer by attaching a resistor and a capacitor to PBFB pin, and a
capacitor to PBTC pin.
Op2 is an input selector and a LINEOUT amplifier. The gain is 24 dB.
The Dolby reference level is –6 dBm (LINEOUT).
The adjustment method of playback equalizer is described in the paragraph (3).
Note)
Usually the TAPEIN pin level is adjusted by attenuator connected to PBOUT pin.
The capacitance value connected to PBFB can be reduced by adjusting the resistance
connected to PBFB to match the PBOUT level.
With this method, the capacitance value can be reduced according to the amount that the
resistance value is increased even for the same cut-off frequency.
(These specifications use the latter method.)
—11—
CXA1911Q
2. Level diagram
P
B
I
N
P
B
O
U
T
T
A
P
E
I
N
L
I
N
E
O
U
T
0dB
–5
–10
–15
–6dBm
Dolby level
–20
–25
–30
–35
–40
–45
–50
–30dBm
–30dBm
VR adjustment
–55
–60
–65
–70
–75
–70dBm (315Hz 160nWb/m)
Fig.2
Note)
This diagram illustrates the case where the Dolby level is aligned by adjusting the resistance
value connected to PBFB.
—12—
CXA1911Q
3. PBEQ adjustment
3
R1
C2
2
3
3
C1
PBFB
PBTC
fc
PBOUT
1
Ri
2
R3
F
PBIN
R
E IREF
1
R4
1) EQ curve gain difference (=adjustment of internal variable R) → IREF resistor
To adjust the EQ curve gain differences (G1 – G2, G1 – G3), the E IREF resistor should be adjusted to
change the internal variable resistance value.
2) AC gain → External resistor R1
The external resistor R1 should be adjusted to adjust the AC gain.
G1 is obtained by the following equation.
G1=20log
R1 + R3
(R3 = 300kΩ)
R1
3) Low-band cut-off frequency → External resistor R1 and capacitor C1
The low-band cut-off frequency (fc) can be determined by the external resistor R1 and external capacitor
C1.
Note)
In this diagram, C1 and R1 are not connected in series, but are connected to PBFB from between
R1 and C2.
This is to prevent the sound quality from deteriorating when using an electrolytic capacitor.
—13—
CXA1911Q
4. MS (internal detection between tracks) adjustment method
3
2
1
G1
G2
1
2
MSTC
25kHz LPF
(in the case of built-in only)
TAPEIN
10dB
MSOUT
DET
100kΩ
64pF
100kΩ
G1
MSLPF
3
C3
G2
1
2
R1
C1
1
R2
C2
2
1) MS gain (FF/NOR mode gain) adjustment → External resistors R1 and R2
MS gain is expressed by the following equations.
G1 = 10 + 20log
R1 + 100k
[dB]
R1
G2 = 10 + 20log
R2 + 100k
[dB]
R2
2) MS low-band cut-off frequency adjustment → External resistors R1 and R2 and external capacitors C1 and
C2
The external resistors R1 and R2 and external capacitors C1 and C2 should be adjusted to adjust the lowband cut-off frequency for the MS frequency response.
3) MS high-band cut-off frequency adjustment → External capacitor C3
The external capacitor C3 should be adjusted to adjust the high-band cut-off frequency for the MS
frequency response. (In this case, G1 and G2 have the same cut-off frequency.)
—14—
CXA1911Q
Characteristics Graphs
Current consump tion vs. Sup p ly voltage
Playb ack equalizer frequency resp onse
Ta=25°C
Ta=25°C
22.0
For no signal
NR OFF, MS OFF
VCC=8.0V
NR OFF, MS OFF
Output level 25dBm constant
50
Gain [dB]
Current consumption [mA]
60
21.5
40
120µs
30
70µs
21.0
50
100
10k
1k
Frequency [Hz]
20.5
5.0
6.0
7.0
8.0
9.0
10.0 11.0 12.0 13.0
OUT
Supply voltage [V]
300k
0.01µ
B typ e decode characteristics
12
33µ
–40dB
10
270
VCC=8.0V
0dB=Dolby Level
–30dB
6
4
–20dB
2
–10dB
0
0dB
50
100
500
1k
Frequency [Hz]
5k
10k
C typ e decode characteristics
Ta=25°C
24
20
–60dB
VCC=8.0V
0dB=Dolby Level
–50dB
16
Decode boost [dB]
Decode boost [dB]
8
–40dB
12
–30dB
8
–20dB
4
0
–10dB
–4
0dB
50
—15—
100
500
1k
Frequency [Hz]
5k
10k
CXA1911Q
Total harmonic distortion (p re-amp lifier b lock)
B typ e total harmonic distortion
Ta=25°C
101
VCC=8.0V
Input : PBFIN1
Output : PBOUT1
RL=2.7k Ω
Input : TAPEIN1
Output : LINEOUT1
VCC=8.0V
0dB=Dolby Level
RL=2.7k Ω
Total harmonic distortion [%]
f=10kHz
Total harmonic distortion [%]
Ta=25°C
100
100
f=1kHz
10-1
10-2
10-1
NR B
f=1kHz
f=100Hz
–8
–24
–20
–16
–12
–8
–4
NR B
f=100kHz
NR OFF
f=1kHz
0
–4
NR B
f=10kHz
0
4
8
Output level [dB]
12
14
Output level [dBm]
Rip p le rejection ratio (PB O UT)
C typ e total harmonic distortion
Ta=25°C
101
100
Ripple elimination ratio [dB]
Total harmonic distortion [%]
Input : TAPEIN1
Output : LINEOUT1
VCC=8.0V
0dB=Dolby Level
RL=2.7k Ω
NR C
f=10kHz
Ta=25°C
–10
Vcc=8.0V
RL=2.7k Ω
–20
–30
–40
–50
–60
NR C
f=100kHz
50
100
500
1k
Frequency [Hz]
10-1
NR C
f=1kHz
10-2
–8
–4
0
4
8
12
Output level [dB]
—16—
5k
10k
CXA1911Q
Cross talk b etween channels (1ch → 2ch)
Rip p ler rejection ratio (LINEO UT)
–10
–30
VCC=8.0V
RL=2.7k Ω
NR OFF
Vcc=8.0V
Input : PBFIN1
Output : LINEOUT2
(LINEOUT1 level constant)
NR OFF
–40
Cross talk [dB]
–20
Ripple elimination ratio [dB]
Ta=25 °C
Ta=25°C
–30
NR B
–40
NR C
–50
–60
–50
–60
–70
100
–70
100
500
1k
5k
1k
500
Frequency [Hz]
5k
10k
10k
Frequency [Hz]
MS b lock gain vs. B lank detection level
B lank detection level frequency resp onse
Ta=25°C
Ta = 25°C
0
VCC = 8.0 V
Input : TAPEIN 1
MSLPF Pin: T120 pF
–10
VCC=8.0V
Input : TAPEIN1
f=1kHz
–30
–40
–30
HPF Gain 20 dB
Input level [dBm]
Input level [dBm]
–20
–40
–50
HPF Gain 40 dB
–50
–60
20
100
1k
Frequency [HZ]
–60
10k
–70
10
—17—
20
30
40
HPF gain [dB]
50
60
CXA1911Q
Unit : mm
40PIN QFP (PLASTIC)
+ 0.35
1.5 – 0.15
+ 0.1
0.127 – 0.05
9.0 ± 0.4
+ 0.4
7.0 – 0.1
0.1
21
30
20
31
A
11
40
1
+ 0.15
0.3 – 0.1
0.65
10
± 0.12 M
(8.0)
+ 0.15
0.1 – 0.1
0.5 ± 0.2
Package Outline
DETAIL A
PACKAGE STRUCTURE
PACKAGE MATERIAL
EPOXY RESIN
SONY CODE
QFP-40P-L01
LEAD TREATMENT
SOLDER / PALLADIUM
PLATING
EIAJ CODE
∗QFP040-P-0707
LEAD MATERIAL
COPPER / 42 ALLOY
PACKAGE WEIGHT
0.2g
JEDEC CODE
—18—