SGS Thomson Microelectronics TDA7432D Datasheet

BASIC FUNCTION AUDIO PROCESSOR

ONE STEREOANDONE MONOINPUTS
MUTE FUNCTION (SOFTWARE AND HARD-

WARE) CONTROLLED
VOLUMECONTROL IN 1dB STEP
BASS ANDTREBLECONTROL IN 2dBSTEP
FULLY PROGRAMMABLE LOUDNESS CON-

TROL
FOURSPEAKERATTENUATORS:

– Independentattenuationcontrol
– Independentmutefunction

ALL FUNCTIONS PROGRAMMABLE VIA

2

CBUS

I

DESCRIPTION

The TDA7432 is a volume, tone (bass and treble)
balance (Left/Right) processor for quality audio
applicationsincar radio and Hi-Fi systems.

Control is accomplished by serial bus microproc­essor interface.

The AC signal setting is obtained by resistor net-

TDA7432

SO20

ORDERING NUMBER: TDA7432D

works and switches combined with operational
amplifiers.

Thanks to the advanced BIPOLAR/CMOS Tech­nology, the external components have been re­duced.

BLOCK DIAGRAM

IN_L

MONO_IN/MUTE

IN_R

S

68nF

3

MUX

4

2

17

MUX

SUPPLYV

20

GND

10µF 2.7nF

68nF

VOL

+ LOUD

VOL

+ LOUD

4.7K
100nF100nF

BASS TREBLE

S BUS DECODER + LATCHES

BASS TREBLE

100nF100nF

4.7K

2.7nF

TRLBOUTLBINLLOUD_L
119106

127851
TRRBOUTRLOUD_R BINRCREF

SPKR

ATT

SPKR

ATT

SPKR

ATT

SPKR

ATT

16

14

18
19

15

13

D95AU357A

LEFT FRONT

LEFT REAR

SCL
SDA

RIGHT FRONT

RIGHT REAR

August 1996

1/10

TDA7432

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

S

T

amb

T

stg

QUICK REFERENCEDATA

Symbol Parameter Min. Typ. Max. Unit

V

S

V

CL

THD Total Harmonic Distortion (V = 1Vrms f = 1kHZ) 0.05 %

S/N Signal to Noise Ratio 102 dB

Sc Channel Separation f = 1kHz 100 dB

Operating Supply Voltage 10.2 V
Operating Temperature Range -40 to 85 °C
Storage Temperature Range -55 to +150 °C

Supply Voltage 7 9 10.2 V
Max. Input Signal Handling 1.3 1.6 Vrms

Volume Control 1dB step -79 +32 dB
Bass Control 2dB step -18 +18 dB
Treble Control2dB step -14 +14 dB
Speaker Attenuators -37.5 0 dB
Mute Attenuation 100 dB

PIN CONNECTION(Top View)

MONO_IN/MUTE

LOUD_R

LOUD_L

BOUT_R

BOUT_L TRR

CREF

IN_R

IN_L

2
3
4
5
6
7

BIN_R

8
9

BIN_L TRL

10

D95AU358

20
19
18
17
16
15
14
13
12
11

GND1
SDA
SCL
V

S

OUT_LF
OUT_RF
OUT_LR
OUT_RR

THERMAL DATA

Symbol Parameter Value Unit

Thermal ResistanceJunction-pins Max. 150 °C/W

2/10

R

th j-pins

APPLICATIONCIRCUIT

TDA7432

68nF

IN_L

3

MUX

4

MONO_IN

/MUTE

IN_R

2

V

17

9V

V

S

100nF

S

MUX

SUPPLY

20

GND

4.7µF 2.7nF

68nF

VOL

+ LOUD

VOL

+ LOUD

4.7K
100nF100nF

BASS TREBLE

S BUS DECODER + LATCHES

BASS TREBLE

100nF100nF

4.7K

2.7nF

TRLBOUTLBINLLOUD_L
119106

127851
TRRBOUTRLOUD_R BINRCREF

SPKR

ATT

SPKR

ATT

SPKR

ATT

SPKR

ATT

16

14

18
19

15

13

D95AU359B

LEFT FRONT

LEFT REAR

SCL
SDA

RIGHT FRONT

RIGHT REAR

3/10

TDA7432

ELECTRICALCHARACTERISTICS

=25°C,VS=9V, RL= 10kΩ,Rg=50Ω,

(T

amb

all variable gains = 0dB, f = 1kHz, unless otherwise specified.)

Symbol Parameter Test Condition Min. Typ. Max. Unit

INPUT SELECTOR

R

IN

V

CL

S

IN

A

MUTE

V

DC

MUTE AT AM INPUT (*)

V

IL

VOLUME CONTROL

G

MAX

A

MAX

A

step

E

A

E

T

V

DC

LOUDNESS CONTROL

A

MAX

A

step

R

LOUD

BASS CONTROL

B

RANGE

B

CUT

A

Step

R

B

TREBLE CONTROL

C

RANGE

A

step

SPEAKER ATTENUATORS

C

RANGE

A

step

A

MUTE

E

A

V

DC

AUDIO OUTPUTS

V

CLIP

G

OUT

R

L

C

L

R

OUT

DC DC Voltage Level 3.7 4 4.3 V

V

(*) The mute function can be activated without using the I2C bus by grounding the AM input when AMis not selected. This causes the input

multiplexer toselect the referencevoltage instead ofan input signal.

Input Resistance 70 100 130 kΩ
Clipping Level d≤0.3% 1.3 1.6 Vrms
Input Separation 70 100 dB
Input Mute Attenuation 70 95 dB
Mute DC Step 0.2 10 mV

Input Low Voltage AM not selected 0.4 V

Max. Gain Note 2 30.5 32 33.5 dB
Max Attenuation 75 79 83 dB
Step Resolution 0.5 1 1.5 dB
Attenuation Set Error G = +20to -20dB -1 0 +1 dB

G = -20 to -60dB -2 2 dB
Tracking Error G = -20 to -60dB 2 dB
DC Steps Adjacent Attenuation Steps,

0.1 4 mV

Range from 0 to -79dB

From 0dB to -79dB 0.5 10 mV

Control Range 14 15 16 dB
Step Resolution 0.5 1 1.5 dB
Internal Resistor 37 50 63 k

Ω

Max. Bass boost 15.5 18 20 dB
Max. Bass cut -20 -18 -15.5 dB
Step Resolution 1 2 3 dB
Internal Feedback Resistance 48 65 82 k

Ω

Control Range ±13 ±14 ±15 dB
Step Resolution 1 2 3 dB

Control Range 36 37.5 39 dB
Step Resolution From 0 to -24dB 0.5 1 1.5 dB
Output Mute Attenuation 70 90 dB
Attenuation Set Error From 0 to -24dB 1 dB
DC Steps Adjacent Attenuation Steps 0.1 4 mV

Clipping Level d = 0.3% 2 2.5 Vrms
Output Gain (fixed) 4 dB
Output Load Resistance AC - connected 3 k

Ω

DC connected to GND 5
Output Load Capacitance 10 nF
Output Impedance 30 100 Ω

4/10

TDA7432

ELECTRICALCHARACTERISTICS

(continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

GENERAL

V

S

I

S

Supply Voltage 6 9 10.2 V
Supply Current 5 8 11 mA

PSRR Power Supply Rejection Ratio 65 80 dB

e

NO

Output Noise 20Hz - 20kHz ”A” - weighted

BW = 200Hz - 20kHz, flat

output muted

S/N Signal to Noise Ratio all gains = 0dB; V

d Distortion V

= 1Vrms 0.05 0.15 %

OUT

= 1Vrms 103 dB

O

4

7.0

5.5

20

Sc Channel Separation 70 80 dB
E

T

Total Tracking Error AV= 0 to -20dB

A

= -20 to -60dB

V

0
0

1
2

BUS INPUTS

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

IO= 1.6mA 0.15 0.4 V
SDA Acknowledge

SOFTWARESPECIFICATION
Interface Protocol

The interfaceprotocolcomprises:
– a start condition (S)
– a chip address byte (the LSBbit determinesread / write transmission)
– a subaddressbyte
– a sequenceof data (N-bytes+ acknowledge)
– a stop condition(P)

µ
µV
µV

dB
dB

V

MSB

CHIP ADDRESS

LSB

MSB

SUBADDRESS

LSB MSB

DATA 1...DATAn

LSB

S 1 0 0 0 1 0 1 R/W ACK X X X I A3A2A1A0ACK DATA ACK P

ACK = Acknowledge
S = Start
P = Stop
MAX CLOCK SPEED 500kbits/s

Auto Increment

If bit I in the subaddressbyte is set to ”1”, the autoincrementof the subaddressis enabled.

5/10

TDA7432

SUBADDRESS

(receivemode)

MSB LSB

X X X I A3A2A1A0

0
0
0
0
0
0
0
0

0
0
0
0
1
1
1
1

0
0
1
1
0
0
1
1

I = Auto increment
X = Not used

DATA BYTE SPECIFICATION

X = not relevant; set to ”1” during testing

Input Selector

MSB LSB

D

D

7

D

6

D

5

D

4

D

3

D

2

0
0
0
0
1

1

0
0
1
1

X
0
1

0
1

Input selector

0

Volume

1

Bass, Treble

0

Speaker attenuator LF

1

Speaker attenuator LR

0

Speaker attenuator RF

1

Speaker attenuator RR

0

Loudness

1

D

0

IN

0

not used

1

mono

0

no input selected

1

mute (low homic)

X

non-symmetrical bass cut (note 1)
symmetrical bass cut
extended bass range
standard bass range ±14dB

FUNCTION

FUNCTION

For example to select the MONO input the Data Byte is: X X X X 0 1 0.
An additionaldirect mute function is included in the SpeakerAttenuators.

Note 1: Basscut for verylow frequencies.

MSB LSB

(*) D

D

7

1
1
1
1
1
1
1

1
1
1

D

6

0
0
0
0
1
1
1

D

5

0
0
1
1
0
0
1

D

4

D

3

D

2

D

1

0
1
0
1
0
1
0

0
0
0

0
0
0

0

0

1

0
1

0
1
1

1

1

1

1

0

+32dB
+16dB

0dB

-16dB

-32dB

-48dB

-64dB
0dB

-1dB

-2dB

-15dB

VOLUME

(*) Loudness = ON

Note 2:
It is not recommended to use a gain more than 20dB for system performance reason. In general, the max. gain should be limited by
software to themaximum value, which is needed for the system.

6/10

Bass, Treble

TDA7432

D4

Input

Selector

0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0

MSB LSB

D

D

D

D

D

D

D

7

6

5

4

3

2

0

0

0

0

0

0

0

0

1

0

1

0

1

0

1

0

1

1

1

1

1

1

1

1

0

1

0

1

0

1

0

1

1

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

1

0

1

0

1

0

1

1

1

1

1

1

1

1

0

1

0

1

0

1

0

1

0

1

0

1

0

0

0

0

1

0

0

1

1

1

0

0

1

0

0

1

1

1

1

1

0

1

1

0

0

0

1

1

0

1

1

0

0

0

0

0

1

0

D

1

0

0

1

0

0

1

1

1

0

0

1

0

0

1

1

1

1

1

0

1

1

0

0

0

1

1

0

1

1

0

0

0

0

Treble Steps

- 14dB

-12dB

-10dB

-8dB

-6dB

-4dB

-2dB
0dB
0dB
+2dB
+4dB
+6dB
+8dB
+10dB
+12dB
+14dB

Bass Steps

-18dB

-16dB

-14dB

-12dB

-10dB

-8dB

-6dB

-4dB

-2dB
0dB
0dB
+2dB
+4dB
+6dB
+8dB
+10dB
+12dB
+14dB
+16dB
+18dB

normal

range

14dB

±

FUNCTION

For example 12dB Treble and -8dB Bass give the followingDATA BYTE: 0 0 1 1 1 0 0 1

Speaker Attenuators

MSB LSB

D

D

7

X
X

D

6

X
X

D

5

0
0

D

4

0
0

D

3

0
0

D

2

0
0

D

1

0
0

0

1

:
X
X
X
X
X
X
X
X

X
X
X
X
X
X
X
X

0
0
0
0
0
0
0
0

1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1

0
0
0
0
1
1
1
1

0
0
1
1
0
1
1
1

0
1
0
1
0
1
0
1

1

X

X

1

X

X

X

X

X

0

SPEAKER ATTENUATOR LF, LR, RF, RR

0dB

-1dB
:

-24dB

-25.5dB

-27dB

-28.5dB

-30dB

-32dB

-34.5dB

-37.5dB

Speaker Mute

7/10

TDA7432

Loudness

MSB LSB

D

D

7

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

D

6

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

D

5

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X

D

4

0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

D

1

D

3

0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1

D

3

D

2

0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1

D1

2

D

1

0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1

0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1

D0

0

0dB

-1dB

-2dB :

-3dB

-4dB

-5dB

-6dB

-7dB

-8dB

-9dB

-10dB

-11dB

-12dB

-13dB

-14dB

-15dB

Loudness flat (Note 3)

LOUDNESS

For example to select -14dBLoudness theData Byte is : XX X 01110.

Note3:
Fiat attenuation, according to the selected byte. The loudnesscan be completely disabled by setting bit D7 in the volume byte to ”0”. In this
case the attenuation is 0dB independent from the loudness settings.

Functional Description

The input selector is able to select 1 stereoinputs
and 1 mono input (AM). The inputs are DC biased
with 100kΩ resistorsto the internal reference volt­age of 3V. The AM input can be use additionally
as hardware mute pin. If this pin is pulled to
ground by an external transistorandAM is not se­lected, the input selector mutes the input (refer­ence voltage selected). The AM part is consid­ered to be switched OFF. If the output of the AM
part is not high ohmic in this condition, a series
resistor of about 20kΩhasto be foreseen.

The volume control can be programmed from a
gain of +32dB to an attenuation of -79dB in 1dB
steps. The maximum gain should be kept as low
as possiblefor system performancereason. It has
to be limited by software to the absolute neces­sary system gain, dependingon the signal source
level and the power amplifier gain.

The bass control acts in a range from +18dB to ­18dB in 2dB steps. The filter response is deter-

8/10

mined by the external filter components. An ex­tensive simulationsoftware is available in order to
supportthe design of the bass filter response with
differentfilterconfigurations.
The extended bass boost range of +18dB allows
the implementationof thesoftware loudnessfunc­tion by additionalbass and treble boost.

The treble control acts in a rangeof ±14dB in 2dB
steps. The external capacitor determines with the
internal resistor of 50KΩ the corner frequencyof
the treble response.

The four speakerattenuatorscanbe controlled in­dependentlyfrom 0 to -37.5dB, which allows the
implementation of balance and fader a the four
speaker system. The attenuation steps size is 1
db from 0 to -24dB and increases nonlinearly up
to the maximum attenuation of 37.5dB. A special
mute bit forces the speaker attenuator into the
muteposition.

All 4 outputs are low distortion push pull outputs,
able to drive a load of 3kΩ.

SO20 PACKAGEMECHANICAL DATA

TDA7432

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 2.65 0.104
a1 0.1 0.3 0.004 0.012
a2 2.45 0.096

b 0.35 0.49 0.014 0.019
b1 0.23 0.32 0.009 0.013

C 0.5 0.020

c1 45 (typ.)

D 12.6 13.0 0.496 0.512
E 10 10.65 0.394 0.419

e 1.27 0.050
e3 11.43 0.450

F 7.4 7.6 0.291 0.299

L 0.5 1.27 0.020 0.050

M 0.75 0.030
S 8 (max.)

mm inch

9/10

TDA7432

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronicsassumes no responsability for the
consequences of use of such information nor for any infringement of patents or otherrights of third parties which may results from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications men­tioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without ex­press written approval of SGS-THOMSON Microelectronics.

 1996 SGS-THOMSONMicroelectronics - Printed in Italy- All Rights Reserved

SGS-THOMSON Microelectronics GROUP OF COMPANIES

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10/10