SGS Thomson Microelectronics TDA7440D Datasheet



DIGITALLY CONTROLLED AUDIO PROCESSOR

INPUTMULTIPLEXER

- 4 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

DESCRIPTION

The TDA7440D is a volume tone (bass and
treble) balance (Left/Right) processor for quality
audio applicationsin Hi-Fisystems.

TDA7440D

TONE CONTROL

SO28

ORDERING NUMBER: TDA7440D

Selectable input gain is provided. Control of all
the functionsis accomplished by serial bus.

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

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

INPUT

G

0/30dB

2dB STEP

G

MULTIPLEXER

+ GAIN

MUXOUTL INL

8 9 18 14 15

VOLUME

VOLUME

10 11 19 12 13 23

MUXOUTR INR TREBLE(R)

TREBLE(L)

TREBLE

I2CBUS DECODER + LATCHES

TREBLE

BIN(L)

R

BASS

BASS

R

BOUT(L)

B

B

BOUT(R)BIN(R)

SPKR

LEFT

SPKR

RIGHT

V

SUPPLY

REF

ATT

ATT

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 (Top view)

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
Storage Temperature Range -55 to 150 °C

C

°

THERMAL DATA

Symbol Parameter Value Unit

R

thj-pin

Thermal ResistanceJunction-pins 85 °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

2/16

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 (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

TDA7440D

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 4 7 10 mA

INPUT STAGE

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

VOLUMECONTROL

C

RANGE

A

A

V

A

R

VMAX

STEP

E

A

E

T

DC

mute

Input Resistance 20 33 50 KΩ

i

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

V

max

0

0.5

Mute Attenuation 80 100 dB

3mV

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

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 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

= -20 to -56dB -2 0 2 dB

A

V

DC Step adjacent attenuation steps 0 3 mV
Mute Attenuation 80 100 dB

mV

3/16

TDA7440D

ELECTRICALCHARACTERISTICS

(continued.)

Symbol Parameter Test Condition Min. Typ. Max. Unit

AUDIOOUTPUTS

VCLIP Clipping Level d = 0.3% 2.1 2.6 VRMS

R

L

R

O

DC DC Voltage Level 3.5 3.8 4.1 V

V

Output Load Resistance 2 KΩ
Output Impedance 10 30 50

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

; 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 1V
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

Ω

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

MUXOUTL INL

G

0/30dB

2dB STEP

G

MULTIPLEXER

+ GAIN

MUXOUTR INR TREBLE(R)

8 9 18 14 15

10 11 19 12 13 23

2.2µF

5.6nF

TREBLE(L)

VOLUME

VOLUME

TREBLE

I2CBUS DECODER +LATCHES

TREBLE

5.6K

100nF 100nF

BIN(L)

R

B

BASS

BASS

R

B

100nF 100nF

5.6K

BOUT(L)

SPKR

LEFT

SPKR

RIGHT

SUPPLY

BOUT(R)BIN(R)

27

ATT

ATT

V

REF

CREF

10µF5.6nF

21
22
20

26

24
25

LOUT

SCL
SDA
DIG_GND

ROUT

V

S

AGND

D98AU885

4/16

TDA7440D

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 TDA7440D audioprocessorprovides 3 bands
tones control.

Bass Stage

Several filter types can be implemented, connect­ing 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

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 factorare computedas follows:

=

F

C

⋅ π⋅√

2

R2 C2 + R2 C1 + RiC1

=

A

V

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 componentsvalues will be:

C1

=

2 ⋅ π ⋅ F

R2 =

− 1

A

V

C

⋅ Ri⋅ Q

A

V

C2

− 1 − Q

2

2 ⋅ π ⋅ C1 ⋅ FC⋅ (AV− 1) ⋅Q

=

Q

A

V

2

⋅ C1

− 1 − Q

2

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.

CREF

The suggested 10µF reference capacitor (CREF)
value can be reduced to 4.7µF if the application
requiresfasterpower ON.

Figure 2:

THD vs. frequency

Figure3:

THDvs. R

LOAD

5/16