SGS Thomson Microelectronics TDA7449L Datasheet
DIGITALLY CONTROLLED AUDIO PROCESSOR
INPUTMULTIPLEXER
- 2 STEREO INPUTS
- SELECTABLEINPUT GAIN FOR OPTIMAL
ADAPTATIONTO DIFFERENT SOURCES
ONE STEREO OUTPUT
VOLUMECONTROL IN 1.0dB STEPS
TWOSPEAKERATTENUATORS:
- TWOINDEPENDENTSPEAKERCONTROL
IN 1.0dBSTEPS FOR BALANCEFACILITY
- INDEPENDENTMUTE FUNCTION
ALL FUNCTION ARE PROGRAMMABLE VIA
SERIALBUS
DESCRIPTION
The TDA7449L is a volume control and balance
(Left/Right) processor for quality audio applications in TV systems.
Selectable input gain is provided. Control of all
the functions is accomplishedby serialbus.
The AC signal setting is obtained by resistor net-
TDA7449L
LOW COST
DIP20
ORDERING NUMBER: TDA7449L
works and switches combined with operational
amplifiers.
Thanks to the used BIPOLAR/CMOSTechnology,
Low Distortion, Low Noise and DC stepping are
obtained.
BLOCK DIAGRAM
L-IN1
L-IN2
R-IN1
R-IN2
MUXOUTL
8
100K
9
100K
7
100K
6
100K
INPUT
G
0/30dB
2dB STEP
G
MULTIPLEXER
+ GAIN
10
VOLUME
I2CBUS DECODER + LATCHES
VOLUME
11 1
MUXOUTR
SPKR ATT
LEFT
SPKR ATT
RIGHT
V
REF
SUPPLY
CREF
5
19
20
18
4
2
3
LOUT
SCL
SDA
DIG_GND
ROUT
V
S
AGND
D98AU868
April 1999
1/13
TDA7449L
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
S
T
amb
T
stg
PIN CONNECTION
Operating Supply Voltage 10.5 V
Operating Ambient Temperature -10 to 85 °C
Storage Temperature Range -55 to 150 °C
CREF
V
PGND
ROUT
LOUT
R_IN2
R_IN1
L_IN1
L_IN2
1
2
S
3
4
5
6
7
8
9 N.C.
19
18
17
16
15
14
13
12
SDA20
SCL
DIG_GND
N.C.
N.C.
N.C.
N.C.
N.C.
MUXOUT(L) 10 MUXOUT(R)11
D98AU869
THERMAL DATA
Symbol Parameter Value Unit
R
thj-pin
Thermal ResistanceJunction-pins 150 °C/W
QUICK REFERENCE DATA
Symbol Parameter Min. Typ. Max. Unit
V
S
V
CL
THD Total Harmonic DistortionV = 1Vrms f = 1KHz 0.01 0.1 %
S/N Signal to Noise Ratio V
S
C
2/13
Supply Voltage 6 9 10.2 V
Max. input signal handling 2 Vrms
= 1Vrms (mode = OFF) 106 dB
out
Channel Separation f = 1KHz 90 dB
Input Gain in (2dBstep) 0 30 dB
Volume Control (1dB step) -47 0 dB
Balance Control 1dB step -79 0 dB
Mute Attenuation 100 dB
TDA7449L
ELECTRICALCHARACTERISTICS
R
= 600Ω, all controls flat (G = 0dB), unless otherwise specified)
G
(refer to the test circuit T
=25°C,VS= 9V,RL= 10KΩ,
amb
Symbol Parameter Test Condition Min. Typ. Max. Unit
SUPPLY
V
S
I
S
SVR Ripple Rejection 60 90 dB
Supply Voltage 6 9 10.2 V
Supply Current 7 mA
INPUT STAGE
G
G
R
V
S
inmin
inman
G
IN
CL
IN
step
Input Resistance 100 KΩ
Clipping Level THD = 0.3% 2 2.5 Vrms
Input Separation The selected input is grounded
80 100 dB
through a 2.2µ capacitor
Minimum Input Gain -1 0 1 dB
Maximum Input Gain 30 dB
Step Resolution 2 dB
VOLUMECONTROL
C
RANGE
A
A
V
A
VMAX
STEP
E
A
E
T
DC
mute
Control Range 45 47 49 dB
Max. Attenuation 45 47 49 dB
Step Resolution 0.5 1 1.5 dB
Attenuation Set Error AV= 0 to-24dB -1.0 0 1.0 dB
A
= -24 to -47dB -1.5 0 1.5 dB
V
Tracking Error AV= 0 to-24dB 0 1 dB
= -24 to -47dB 0 2 dB
A
V
DC Step adjacent attenuation steps
from 0dB to A
V
max
0
0.5
3mV
Mute Attenuation 80 100 dB
SPEAKERATTENUATORS
C
RANGE
S
V
A
STEP
E
A
DC
mute
Control Range 76 dB
Step Resolution 0.5 1 1.5 dB
Attenuation Set Error AV= 0 to-20dB -1.5 0 1.5 dB
A
= -20 to -56dB -2 0 2 dB
V
DC Step adjacent attenuation steps 0 3 mV
Mute Attenuation 80 100 dB
AUDIO OUTPUTS
V
CLIP
R
L
R
O
V
DC
Clipping Level d = 0.3% 2.1 2.6 V
Output Load Resistance 2 KΩ
Output Impedance 10 40 70
DC Voltage Level 3.8 V
mV
RMS
Ω
GENERAL
E
NO
E
S/N Signal to Noise Ratio Allgains 0dB; V
S
C
d Distortion A
Output Noise All gains = 0dB;
BW = 20Hz to 20KHz flat
Total TrackingError AV= 0 to-24dB 0 1 dB
t
A
= -24 to -47dB 0 2 dB
V
Channel Separation Left/Right 80 100 dB
=0;VI=1V
V
BUS INPUT
515µV
O =1VRMS ; 106 dB
; 0.01 0.08 %
RMS
3/13
TDA7449L
ELECTRICALCHARACTERISTICS
(continued.)
Symbol Parameter Test Condition Min. Typ. Max. Unit
BUS INPUT
V
IL
V
IH
I
IN
V
O
Input Low Voltage 1V
Input High Voltage 3 V
Input Current VIN= 0.4V -5 5
Output Voltage SDA
IO = 1.6mA 0.4 0.8 V
Acknowledge
TEST CIRCUIT
MUXOUTL
10
8
L-IN1
0.47µF
L-IN2
0.47µF
R-IN1
0.47µF
100K
9
100K
7
100K
G
0/30dB
2dB STEP
VOLUME
I2CBUS DECODER + LATCHES
SPKR ATT
LEFT
19
20
18
5
LOUT
SCL
SDA
DIG_GND
A
µ
6
R-IN2
0.47µF
100K
INPUT MULTIPLEXER
G
+ GAIN
APPLICATIONSUGGESTIONS
The first and the last stages are volume control
blocks. The control range is 0 to -47dB (mute) for
the first one, 0 to -79dB (mute) for the last one.
Both of them have 1dB step resolution.
The very high resolutionallows the implementation
of systemsfreefromanynoisyacousticaleffect.
10µF
4
2
3
D98AU870
ROUT
V
S
AGND
VOLUME
11 1
MUXOUTR
SPKR ATT
RIGHT
V
REF
SUPPLY
CREF
The TDA7449L audioprocessor provides 2 bands
tonescontrol.
CREF
The suggested 10µF reference capacitor (CREF)
value can be reduced to 4.7µF if the application
requiresfasterpower ON.
4/13
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