SGS Thomson Microelectronics TDA7448 Datasheet
6 CHANNEL VOLUME CONTROLLER
■ 6 CHANNEL INPUTS
■ 6 CHANNEL OUTPUTS
■ VOLUME ATTENUATION RANGE OF
0 TO -79dB
■ VOLUME CONTROL IN 1.0dB STEPS
■ 6 CHANNEL INDEPENDENT CONTROL
■ ALL FUNCTION ARE PROGRAMMABLE VIA
SERIAL BUS
DESCRIPTIO
The TDA7448 is a 6 channel volume controller for
quality audio applications in Multi-Channels Audio
Systems
Thanks to the used BIPOLAR/CMOS Technology,
TDA7448
PRODUCT PREVIEW
SO20
ORDERING NUMBER: TDA7448
Low Distortion, Low Noise and DC stepping are obtained.
BLOCK DIAGRAM
2
IN1 OUT1
50K
19
IN2
50K
3
IN3
50K
18
IN4
50K
4
IN5
50K
17
IN6
50K
11
GND
CREF
20
VOLUME
VOLUME
VOLUME
VOLUME
VOLUME
VOLUME
SUPPLY
2
I
C BUS
DECODER
1
V
S
7
14
6
15
5
16
10
9
12
D02AU1396
OUT2
OUT3
OUT4
OUT5
OUT6
SCL
SDA
ADDR
December 2002
This is preliminary information on a new product now in development. Details are subject to change without notice.
1/13
TDA7448
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
Operating Supply Voltage 10.5 V
S
Operating Ambient Temperature -10 to 85 °C
Storage Temperature Range -55 to 150 °C
T
T
V
amb
stg
PIN CONNECTION
V
IN1
IN3
IN5
OUT5
OUT3
OUT1
N.C.
SDA
S
1
2
3
4
5
6
7
8
9 ADDR
SCL 10 GND
D02AU1397
20
19
18
17
16
15
14
13
12
11
CREF
IN2
IN4
IN6
OUT6
OUT4
OUT2
N.C.
THERMAL DATA
Symbol Parameter Value Unit
R
th j-pin
thermal Resistance junction-pins 150 °C/W
QUICK REFERENCE DATA
Symbol Parameter Min. Typ. Max. Unit
V
S
V
CL
THD Total Harmonic Distortion V = 1Vrms f =1KHz 0.01 0.1 %
S/N Signal to Noise Ratio Vout = 1Vrms 100 dB
S
C
Supply Voltage 4.75 9 10 V
Max Input Signal Handling 2 Vrms
Channel Separation f = 1KHz 90 dB
Volume Control (1dB step) -79 0 dB
Mute Attenuation 90 dB
2/13
TDA7448
ELECTRICAL CHARACTERISTCS
(refer to the test circuit T
Symbol Parameter Test Condition Min. Typ. Max. Unit
SUPPLY
V
SVR Ripple Rejection 80 dB
Supply Voltage 4.75 9 10 V
S
I
Supply Current 7 mA
S
INPUT STAGE
R
V
S
Input Resistance 35 50 6 5 KΩ
IN
Clipping Level THD = 0.3% 2 2.5 Vrms
CL
Input Separation The selected input is grounded
IN
VOLUME CONTROL
C
RANGE
A
VMAX
A
STEP
E
E
V
A
mute
Control Range 79 dB
Max. Attenuation 79 dB
Step Resolution 0.5 1 1.5 dB
Attenuation Set Error AV = 0 to -24dB -1 0 1 dB
A
Tracking Error AV = 0 to -24dB -1 0 1 dB
T
DC Step adyacent attenuation steps -3 0 3 mV
DC
Mute Attenuation 90 db
AUDIO OUTPUTS
V
CLIP
R
V
Clipping Level THD = 0.3% 2 2.5 Vrms
Output Load Resistance 2 KΩ
L
DC Voltage Level 4.5 V
DC
GENERAL
E
S/N Signal to Noise Ratio All gains = 0dB; V
S
THD Distortion A
Output Noise BW = 20Hz to 20KHz
NO
Channel Separation left/Right 80 90 dB
C
BUS INPUT
V
V
I
V
Input Low Voltage 1V
Il
Input High Voltage 2.5 V
IH
Input Current VIN = 0.4V -5 5 µA
IN
Output Voltage SDA
O
Achnowledge
= 25°C, VS = 9V, RL = 10KΩ, RG = 600Ω, unless otherwise specified)
amb
90 dB
through a 2.2µ capacitor
A
= -24 to -79dB -2.0 0 2.0 dB
V
A
= -24 to -79dB -2 0 2 dB
V
10 15 µV
All gains = 0dB, Flat
= 1Vrms 100 dB
O
= 0; VI = 1Vrms 0.01 0.1 %
V
IO = 1.6mA 0.4 0.8 V
3/13
TDA7448
Figure 1. Tes t circuit
0.47µF
IN1
GND
CREF
2
IN2
19
IN3
3
IN4
18
IN5
4
IN6
17
11
20
IN1
0.47µF
IN2
0.47µF
IN3
0.47µF
IN4
0.47µF
IN5
0.47µF
IN6
10µF
50K
50K
50K
50K
50K
50K
VOLUME
VOLUME
VOLUME
VOLUME
VOLUME
VOLUME
SUPPLY
2
I
C BUS
DECODER
1
V
S
7
14
6
15
5
16
10
9
11
D02AU1406
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
SCL
SDA
ADDR
APPLICATION SUGGESTIONS
The volume control range is 0 to -79dB, by 1dB step
resolution.
The very high resolution allows the i mplementation of
systems free from any noise acoustical effect.
CREF
The suggested 10µF reference capacitor (CREF)
value can be reduced to 4.7
µ
F if the application re-
quires faster power ON.
Figure 2. THD vs. frequency
Figure 3. THD vs. R
LOAD
Figure 4. Channel separation vs. frequency
4/13
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