STMicroelectronics TDA7440D Schematic [ru]
®
DIGITALLY CONTROLLED AUDIO PROCESSOR
INPUT MULTIPLEXER
- 4 STEREO INPUTS
- SELECTABLE INPUT GAIN FOR OPTIMAL
ADAPTATION TO DIFFERENT SOURCES
ONE STEREO OUTPUT
TREBLE AND BASS CONTROL IN 2.0dB
STEPS
VOLUME CONTROL IN 1.0dB STEPS
TWO SPEAKER ATTENUATORS:
- TWO INDEPENDENT SPEAKER CONTROL
IN 1.0dB STEPS FOR BALANCE FACILITY
- INDEPENDENT MUTE FUNCTION
ALL FUNCTION ARE PROGRAMMABLE VIA
SERIAL BUS
DESCRIPTION
The TDA7440D is a volume tone (bass and
treble) balance (Left/Right) processor for quality
audio applications in Hi-Fi systems.
TDA7440D
TONE CONTROL
SO28
ORDERING NUMBER:
Selectable input gain is provided. Control of all
the functions is accomplished by serial bus.
The AC signal setting is obtained by resistor networks and switches combined with operational
amplifiers.
Thanks to the used BIPOLAR/CMOS Technology,
Low Distortion, Low Noise and DC stepping are
obtained
TDA7440D
BLOCK DIAGRAM
4
L-IN1
5
L-IN2
6
L-IN3
7
L-IN4
3
R-IN1
2
R-IN2
1
R-IN3
28
R-IN4
100K
100K
100K
100K
100K
100K
100K
100K
G
0/30dB
2dB STEP
G
INPUT MULTIPLEXER
+ GAIN
BASS
BASS
R
R
BOUT(L)
B
B
BOUT(R)BIN(R)
MUXOUTL INL
8 9 18 14 15
VOLUME
VOLUME
10 11 19 12 13 23
MUXOUTR INR
TREBLE(L)
TREBLE
I2CBUS DECODER + LATCHES
TREBLE
TREBLE(R)
BIN(L)
SPKR ATT
LEFT
SPKR ATT
RIGHT
V
REF
SUPPLY
CREF
27
21
22
20
26
24
25
LOUT
SCL
SDA
DIG_GND
ROUT
V
S
AGND
D98AU883
April 1999
1/16
TDA7440D
PIN CONNECTION (To p vi e w)
R_IN3
R_IN2
R_IN1
L_IN1
L_IN2 V
L_IN3
L_IN4
MUXOUTL
IN(L)
MUXOUT(R)
IN(R)
BIN(R)
BOUT(R)
BIN(L)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
D98AU884
28
27
26
25
24
22
21
20
19
18
17
16
15
R_IN4
LOUT
ROUT
AGND
S
CREF23
SDA
SCL
DIG-GND
TREBLE(R)
TREBLE(L)
N.C.
N.C.
BOUT(L)
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
V
S
T
amb
T
stg
Operating Supply Voltage 10.5 V
Operating Ambient Temperature -10 to 85 °C
Storage Temperature Range -55 to 150 °C
THERMAL DATA
Symbol Parameter Value Unit
R
th j-pin
Thermal Resistance Junction-pins 85 °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 V
S
C
2/16
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 (2dB step) 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
TDA7440D
ELECTRICAL CHARACTERISTICS
= 600Ω, all controls flat (G = 0dB), unless otherwise specified)
R
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 4 7 10 mA
INPUT ST AGE
G
G
R
V
S
inmin
inman
G
IN
CL
IN
step
Input Resistance 70 100 130 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 29 30 31 dB
Step Resolution 1.5 2 2.5 dB
VOLUME CONTROL
C
RANGE
A
A
V
A
R
i
VMAX
STEP
E
A
E
T
DC
mute
Input Resistance 20 33 50 KΩ
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
A
= -24 to -47dB 0 2 dB
V
DC Step adjacent attenuation steps
from 0dB to A
max
V
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 33 44 55 KΩ
TREBLE CONTROL (1)
Gt Control Range Max. Boost/cut +13.0 +14.0 +15.0 dB
T
STEP
Step Resolution 1 2 3 dB
SPEAKER AT TENUATO RS
C
RANGE
S
STEP
E
A
V
DC
A
mute
NOTE1:
1) The device is functionally good at Vs = 5V. a step down, on Vs, to 4V does’t reset the device.
2) BASS and TREBLE response: The center frequency and the response quality can be chosen by the external circuitry.
Control Range 70 76 82 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
3/16
TDA7440D
ELECTRICAL CHARACTERISTICS
(continued.)
Symbol Parameter Test Condition Min. Typ. Max. Unit
AUDIO OUTPUTS
V
R
R
V
CLIP
L
O
DC
Clipping Level d = 0.3% 2.1 2.6 V
Output Load Resistance 2 KΩ
Output Impedance 10 30 50 Ω
DC Voltage Level 3.5 3.8 4.1 V
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 = 0 to -24dB 0 1 dB
A
= -24 to -47dB 0 2 dB
V
= 1V
O
; 95 106 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 1 V
Input High Voltage 3 V
Input Current VIN = 0.4V -5 0 5 µA
Output Voltage SDA
IO = 1.6mA 0.4 0.8 V
Acknowledge
RMS
TEST CIRCUIT
0.47µF
0.47µF
0.47µF
0.47µF
0.47µF
0.47µF
0.47µF
0.47µF
L-IN1
L-IN2
L-IN3
L-IN4
R-IN1
R-IN2
R-IN3
R-IN4
2.2µF
4
100K
5
100K
6
100K
7
100K
3
100K
2
100K
1
100K
28
100K
INPUT MULTIPLEXER
MUXOUTL INL
G
0/30dB
2dB STEP
G
+ GAIN
MUXOUTR INR
8 9 18 14 15
10 11 19 12 13 23
2.2µF
5.6nF
TREBLE(L)
VOLUME
VOLUME
TREBLE
I2CBUS DECODER + LATCHES
TREBLE
TREBLE(R)
5.6K
100nF 100nF
BIN(L)
R
B
BASS
BASS
R
B
100nF 100nF
5.6K
BOUT(L)
SPKR ATT
LEFT
SPKR ATT
RIGHT
V
SUPPLY
BOUT(R)BIN(R)
27
LOUT
21
SCL
22
SDA
20
DIG_GND
26
ROUT
REF
24
V
S
25
AGND
D98AU885
CREF
10µF5.6nF
4/16
TDA7440D
APPLICATION SUGGES TION S
The first and the last stages are volume control
blocks. The control range is 0 t o -47dB (mute) for
the first one, 0 t o -79dB (mute) for the last one.
Both of them have 1dB step resolution.
The very high resolution allows the implementation
of systems free from any noisy acoustical effect.
The TDA7440D audioprocessor provides 3 bands
tones control.
Bass Stage
Several filter types can be implemented, connecting external components to the Bass I N 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
R
2
D95AU313
C
2
C
1
ternal and R2,C1,C2 external) the centre frequency Fc, the gain Av at max. boost and the filter Q factor are computed as follows:
=
F
C
AV =
⋅√
2 ⋅ π
R2 C2 + R2 C1 + Ri C1
R2 C1 + R2 C2
√
R1 ⋅ R2 ⋅ C1 ⋅ C2
Q =
R2 C1 + R2 C2
1
R1 ⋅ R2 ⋅ C1 ⋅ C2
Viceversa, once Fc, Av, and Ri internal value are
fixed, the external components values will be:
2
⋅ C1
Q
AV − 1 − Q
2
C1 =
A
− 1
V
2 ⋅ π ⋅ F
R2 =
⋅ Ri ⋅ Q
C
2 ⋅ π ⋅ C1 ⋅ FC ⋅ (AV − 1) ⋅Q
C2 =
A
− 1 − Q
V
2
Treble Stage
The treble stage is a high pass filter whose time
constant is fixed by an internal resistor (25K
typical) and an external capacitor connected between treble pins and ground
Typical responses are reported in Figg. 10 to 13.
CREF
The suggested 10µF reference capacitor (CREF)
value can be reduced to 4.7µF if the application
requires faster power ON.
Ω
Figure 2:
THD vs. frequency
Figure 3:
THD vs. R
LOAD
5/16
TDA7440D
Figure 4:
Figure 6:
Channel separation vs. frequency
Treble response
Figure 5:
Bass response
Ω
Ri = 44k
C9 = C10 = 100nF (Bout, Bin)
R3 = 5. 6k
Ω
6/16
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