SGS Thomson Microelectronics TDA7449 Datasheet
DIGITALLY CONTROLLED AUDIO PROCESSOR
INPUTMULTIPLEXER
- 2 STEREO INPUTS
- SELECTABLEINPUT GAIN FOR OPTIMAL
ADAPTATIONTO DIFFERENT SOURCES
ONE STEREO OUTPUT
TREBLE, AND BASS CONTROL IN 2.0dB
STEPS
VOLUMECONTROL IN 1.0dB STEPS
TWOSPEAKERATTENUATORS:
- TWOINDEPENDENTSPEAKERCONTROL
IN 1.0dBSTEPS FOR BALANCEFACILITY
- INDEPENDENT MUTE FUNCTION
ALL FUNCTION ARE PROGRAMMABLE VIA
SERIALBUS
TONE CONTROL
DIP20
ORDERING NUMBER:
TDA7449
TDA7449
DESCRIPTION
The TDA7449 is a volume tone (bass and treble)
balance (Left/Right) processor for quality audio
applicationsin TV systems.
Selectable input gain is provided. Control of all
the functions is accomplishedby serialbus.
BLOCK DIAGRAM
MUXOUTL
10 16 15 14
8
L-IN1
L-IN2
R-IN1
R-IN2
100K
9
100K
7
100K
6
100K
G
0/30dB
2dB STEP
G
VOLUME
VOLUME
The AC signal setting is obtained by resistor networks and switches combined with operational
amplifiers.
Thanks to the used BIPOLAR/CMOSTechnology,
Low Distortion, Low Noise and DC stepping are
obtained.
TREBLE(L)
TREBLE
I2CBUS DECODER + LATCHES
TREBLE
BIN(L)
BASS
BASS
BOUT(L)
R
B
SPKR
LEFT
SPKR
RIGHT
5
ATT
ATT
V
REF
19
20
18
4
LOUT
SCL
SDA
DIG_GND
ROUT
April 1999
INPUT
MULTIPLEXER
+ GAIN
R
B
11 17 12 13 1
MUXOUTR TREBLE(R)
BIN(R) BOUT(R)
SUPPLY
CREF
2
V
3
AGND
D98AU847A
S
1/17
TDA7449
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 BIN(R)
19
18
17
16
15
14
13
12
SDA20
SCL
DIG_GND
TREBLE(R)
TREBLE(L)
BIN(L)
BOUT(L)
BOUT(R)
MUXOUT(L) 10 MUXOUT(R)11
D98AU848
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
2/17
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
Treble Control (2dB step) -14 +14 dB
Bass Control (2dB step) -14 +14 dB
Balance Control 1dB step -79 0 dB
Mute Attenuation 100 dB
TDA7449
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
BASS CONTROL(1)
Gb Control Range Max. Boost/cut +12.0 +14.0 +16.0 dB
B
STEP
R
B
Step Resolution 1 2 3 dB
Internal Feedback Resistance 18.75 25 31.25 KΩ
TREBLECONTROL(1)
Gt Control Range Max. Boost/cut +13.0 +14.0 +15.0 dB
T
STEP
Step Resolution 1 2 3 dB
SPEAKERATTENUATORS
C
RANGE
S
STEP
E
A
V
DC
A
mute
NOTE1:
1) The device is functionally goodat Vs = 5V. a step down,on Vs, to 4V does’t reset thedevice.
2) BASS and TREBLE response: The centerfrequency and the response quality can be chosen by the external circuitry.
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
mV
3/17
TDA7449
ELECTRICALCHARACTERISTICS
(continued.)
Symbol Parameter Test Condition Min. Typ. Max. Unit
AUDIOOUTPUTS
VCLIP ClippingLevel d = 0.3% 2.1 2.6 VRMS
R
L
R
O
DC DC Voltage Level 3.8 V
V
Output Load Resistance 2 KΩ
Output Impedance 10 40 70
GENERAL
E
NO
E
t
S/N Signal to Noise Ratio All gains 0dB; V
S
C
d Distortion A
Output Noise All gains = 0dB;
515µV
BW = 20Hz to 20KHz flat
Total Tracking Error AV= 0to -24dB 0 1 dB
A
= -24to -47dB 0 2 dB
V
O
=1V
; 106 dB
RMS
Channel Separation Left/Right 80 100 dB
=0;VI=1V
V
; 0.01 0.08 %
RMS
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 µA
Output Voltage SDA
IO= 1.6mA 0.4 0.8 V
Acknowledge
Ω
4/17
P.C.Board
TEST CIRCUIT
TDA7449
R2 2K
C9
5.6nF
J5
IN1L
J3
RCA
J2
RCA
GND
1
IN1L
2
GND
3
J4
IN2L
4
GND
5
CON3
IN1R
IN2R
1
GND
2
J1
IN1R
3
GND
4
CON
MOUTL
1
GND
2
J5
MOUTR
3
GND
4
CON4
C3 0.47µF
C4 0.47µF
C1 0.47µF
C2 0.47µF
L-IN1
L-IN2
R-IN2
R-IN1
8
100K
9
100K
6
100K
7
100K
INPUT
MUXOUTL
G
0/30dB
2dB STEP
G
MULTIPLEXER
+ GAIN
MUXOUTR TREBLE(R)
TREBLE(L)
10 16 15 14
VOLUME
VOLUME
11 17 12 13 1
5.6nF
150nF 330nF
C8C7
BIN(L)
R
B
TREBLE
I2CBUS DECODER+ LATCHES
TREBLE
C10
BASS
BASS
R
B
BOUT(R)
C5 C6
BIN(R)
150nF 330nF
R1
2K
BOUT(L)
SPKR
SPKR
RIGHT
SUPPLY
LEFT
V
OUT_L
+V8
GND
C12
22µF
1
2
3
4
CON4
1
2
3
4
CON4
1
2
CON2
J8
J9
J10
J6
J7
OUT_R
+9 V
+9V
OUT_L
OUT_ R
JP1
JUMPER
C13
100nF
5
C11
10µF
LOUT
DIG_GND
18
SCL
19
SDA
20
4
ROUT
R3 30
3
AGND
2
V
S
D98AU849A
ATT
ATT
REF
CREF
5/17
TDA7449
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 resolution allows the implementation
of systems freefromanynoisyacousticaleffect.
The TDA7449 audioprocessor provides 2 bands
tones control.
Bass, Stages
The Bass cell has an internal resistor Ri = 25K
Ω
typical.
Several filter types can be implemented, connect-
ing external components to the BassIN and OUT
pins.
The fig.1 refers to basic T Type Bandpass Filter
starting from the filter component values (R1 in-
Figure 1.
Ri internal
OUTIN
C
1
C
2
ternal and R2,C1,C2 external) the centre frequency Fc, the gain Av at max. boost and the filter Q factorare computedas follows:
=
F
C
2
⋅ π⋅√
C2 + R2 C1+ Ri C1
R2
=
A
V
R2 C1 + R2 C2
√
Q =
R2 C1
1
Ri, R2, C1, C2
+
Ri R2
C1 C2
+ R2 C2
Viceversa, once Fc, Av, and Ri internal value are
fixed, the external componentsvalues will be:
2
Q
=
⋅ C1
− 1)Q
2
(A
V
2
C1
A
− 1
V
=
π ⋅ R
2 ⋅
R2 =
⋅ Q
i
− 1 − Q
A
V
2 ⋅ π ⋅ C1 ⋅ FC⋅ (AV− 1) ⋅Q
C2
TrebleStage
The treble stage is a high pass filter whose time
constant is fixed by an internal resistor (25KΩ
typical) and an external capacitor connected between treble pins andground
Typical responsesare reported in Figg. 10 to 13.
Figure 2:
R
THD vs. frequency
2
D95AU313
CREF
The suggested 10µF reference capacitor (CREF)
value can be reduced to 4.7µF if the application
requiresfasterpower ON.
Figure3:
THDvs. R
LOAD
6/17
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