SGS Thomson Microelectronics TDA7435D Datasheet

DIGITALLY CONTROLLED AUDIO PROCESSOR

WITH LOUDSPEAKERS EQUALIZER

INPUT

- FOURHIGHPASS CHANNELS

- TWOAUX STEREO CHANNELS
VOLUME CONTROL IN 1dB STEPS WITH

GAIN UPTO 15dB
SOFTMUTE AND DIRECT MUTE
FOURAUXILIARYCHANNELS:

- TWOSPEAKERSCONTROL IN 1dB STEP

- TWOCHANNELS MULTIPLEXEDWITH
THEHIGH PASSCHANNELS

ALL FUNCTIONS PROGRAMMABLE VIA SE-

2

RIAL I

DESCRIPTION

The audioprocessor TDA7435 is an upgrade of
the TDA731X audioprocessorfamily.

Due to a highly linear signal processing, using
CMOS-switching techniques instead of standard
bipolar multipliers, very low distortion and very
low noiseare obtained.

CBUS

TDA7435

SO28

ORDERING NUMBER: TDA7435D

A second programmable high pass filtering pro­videsthe loudspeakersequalization.

The soft Mute function is implemented andcanbe
activatedin twoways:

1 Viaserial bus(Mute byte,bit D0)
2 Directlyon pin 3 through an I/Oline of the mi-

crocontroller

Very low DC stepping is obtained by use of a
BICMOStechnology.

BLOCK DIAGRAM

CSM

HP FL 1
HP FL 2

HP FR 1
HP FR 2

HP RL 1
HP RL 2

HP RR 1
HP RR 2

AUX 2 INL

AUX 2 IN R

AUX 1 INL

AUX 1 IN R AUX 1 OUT R

22

HP FILTER

21

20

HP FILTER

19

18

HP FILTER

17

16

HP FILTER

15
6
7

1

2

0-15dB/1dB step

SOFT

MUTE

GAIN

SDA SCL DGND AGND CREF V

3

2

I

C BUS SUPPLY

MUX

ATTENUATOR

0/-79dB

ATTENUATOR

0/-79dB

CC

282324252627

12

10

11

13

14

9

8

5

4

D96AU437A

OUT REF

HP FL OUT

HP FR OUT

HP RL OUT

HP RR OUT

AUX 2 OUT L

AUX 2 OUT R

AUX 1 OUT L

November 1996

1/10

TDA7435

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

S

T

amb

T

stg

PIN CONNECTION

Operating Supply Voltage 10.5 V
Operating Ambient Temperature -40 to85 °C
Storage Temperature Range -55 to150 °C

AUX 1 INL

AUX 1 INR

CSM

AUX 1 OUT R

AUX 1 OUT L

AUX 2 INL

AUX 2 INR

AUX 2 OUT R

AUX 2 OUT L HP FR 1

HP FL OUT HP FR 2

HP FR OUT

OUT REF

HP RL OUT HP RR 1

1
2
3
4
5
6
7
8
9
10

12
13

28
27
26
25
24
23
22
21
20
19
18
17
16
1514HP RR OUT HP RR 2

D96AU438

V

CC

SDA
SCL
DGND
AGND
CREF
HP FL 1
HP FL 2

HP RL 111
HP RL 2

THERMAL DATA

Symbol Parameter Value Unit

R

th j-amb

Thermal ResistanceJunction-pins 65 °C/W

QUICK REFERENCE DATA

Symbol Parameter Min. Typ. Max. Unit

V

S

V

CL

THD Total Harmonic DistortionV = 1Vrms f = 1KHz 0.01 0.08 %

S/N Signal to Noise Ratio 106 dB

S

C

2/10

Supply Voltage 6 9 10.2 V
Max. input signal handling 2.1 2.6 Vrms

Channel Separation f = 1KHz 80 dB
Input Gain AUX1 1dB step 0 15 dB

TDA7435

ELECTRICALCHARACTERISTICS (VS= 9V; RL= 10KΩ;Rg=50Ω;T

=25°C; all gains= 0dB;

amb

f = 1KHz. Refer to the test circuit, unless otherwisespecified.)

Symbol Parameter Test Condition Min. Typ. Max. Unit

INPUTSTAGE:AUX1

G

G

G

R

V

S

I MIN

I MAX

step

E

V

CL

a

DC

Input Resistance 24 33 42 KΩ

I

Clipping Level d ≤ 0.3% 2.1 2.6 V
Input Separation 70 80 dB

I

Minimum InputGain -0.75 0 0.75 dB
Maximum Input Gain 13.75 15 16.25 dB
Step Resolution 0.5 1.0 1.5 dB
Set Error -1.25 0 1.25 dB
DC Steps Adiacent Gain Steps 0.5 10 mV

to G

G

IIN

IMAX

2.5 mV

SPEAKERATTENUATORS - AUX 1

C

A

RANGE

A

step

MUTE

E

A

V

DC

Control Range 79 dB
Step Resolution Av = 0 to -40dB 0.5 1 1.5 dB
Output Mute Attenuation Data Word = 1111XXXX 80 105 dB
Attenuation Set Error Av = 0 to -40dB 1.5 dB
DC Steps Adjacent Attenuation Steps 0 3 mV

AUDIO OUTPUT(Pin 4 - 5, 8 - 9, 10 - 14)

V

clip

R

L

R

O

V

DC

Clipping Level d = 0.3% 2.1 2.6 Vrms
Output Load Resistance 2 K
Output Impedance 20 30 100
DC VoltageLevel 3.5 3.8 4.1 V

STAGE:AUX2

R

V

CL

S

G

Input Resistance 24 33 42 K

I

Clipping Level 2.1 2.6 Vrms
Input Separation 70 80 dB

I

Gain -0.75 0 0.75 dB

I

Input Mute 80 100 dB

RMS

Ω

Ω

Ω

STAGE:HP FILTER

R1 Resistanceat pin HP1 HIGHPASSBYTE
R2 Resistanceat pin HP2 1 MΩ

V

CL

Clipping Level d ≤ 0.3% 2.1 2.6 Vrms

D3 = 1 XXXX1XXX

120 170 220 KΩ

SOFTMUTE

A

T

T

MUTE

DON

DOFF

Mute Attenuation 40 50 dB
ON Delay Time C

=22nF; 0 to-20dB; I =I

CSM
CSM = 22nF;0 to-20dB; I = IMIN 10 30 50 ms

C

0.7 1 2 ms

MAX

OFF Current VCSM =0V;I= IMAX 60 160 µA

CSM = 0V;I =IMIN 110 210 µA

V

3/10

TDA7435

ELECTRICALCHARACTERISTICS (continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

THSM

R

INT

V

SMH

V

SML

GENERAL

V

CC

I

CC

PSRR Power Supply Rejection Ratio f = 1KHz 60 70 dB

e

NO

S/N Signal to Noise Ratio All Gains = 0dB; V

S

C

d Distortion V

BUS INPUTS

V

IL

V

lN

I

lN

V

O

Note 1: WIN represents the MUTE programming bit pair D6,D5for the zero crossing window threshold
Note 2: Internallpullup resistor to Vs/2; ”LOW” = softmute active

Soft MuteThreshold 2.3 V
Pullup Resistor (pin 3) (note 2) 100 KΩ
(pin 3) Level High 3.5 V
(pin 3) Level Low Soft Mute Active 1 V

Supply Voltage 6 9 10.2 V
Supply Current 7 11 15 mA

Output Noise OutputMuted (B= 20to20kHzflat) 3.5 µV

All Gains0dB(B =20to 20kHzflat) 5 15

O

=1V

rms

106 dB

Channel Separation 70 80 dB

=1V 0.01 0.08 %

IN

Input Low Voltage 1V
Input HighVoltage 3 V
Input Current VIN = 0.4V -5 5 µA
Output Voltage SDA

IO= 1.6mA 0.4 V

Acknowledge

V

µ

Figure 1: HP Filter.

100nF 100nF

HP2

56K

18.7K

9.3K

7.6K

4.3K

3.5K

52.5K

HP1

6.2K 3.5K 2.1K 3.8K 4.6K 9.3K 28K

28K

56K

+

-

R1 = EQUIVALENTRESISTANCE AT PIN
R2 = EQUIVALENTRESISTANCE AT PIN HP2

D96AU439

HP1

4/10

TDA7435

2

C BUS INTERFACE

I

Data transmission from microprocessor to the
TDA7435 and viceversa takes place thru the 2
wires I

2

C BUS interface, consisting of the two
lines SDA and SCL (pull-up resistors to positive
supply voltage mustbe externally connected).

Data Validity

As shown in fig. 2, the data on the SDA line must
be stable during the high period of the clock. The
HIGH and LOW state of the data line can only
change when the clock signal on the SCL line is
LOW.

Start and StopConditions

As shown in fig.3 a start condition is a HIGH to
LOW transition of the SDA line while SCL is
HIGH. The stop condition isa LOW to HIGH tran­sition of the SDA linewhile SCL is HIGH.
A STOP conditions must be sent before each
START condition.

Byte Format

Every byte transferred to the SDA line must con­Figure 2: Data Validity on the I

2

CBUS

tain 8 bits. Each byte must be followed by an ac­knowledgebit. The MSBis transferredfirst.

Acknowledge

The master(µP) puts a resistive HIGH level on the
SDA line during the acknowledge clock pulse (see
fig. 4). The peripheral (audioprocessor) that ac­knowledges has to pull-down (LOW) the SDA line
during the acknowledge clock pulse, so that the
SDAline is stableLOWduringthis clockpulse.
The audioprocessor which has been addressed
hasto generatean acknowledgeafterthereception
ofeachbyte,otherwisethe SDAline remainsat the
HIGHlevelduring the ninth clockpulsetime.In this
case the master transmitter can generate the
STOPinformationin orderto abortthetransfer.

Transmissionwithout Acknowledge

Avoiding to detect the acknowledge of the audio­processor, the µP can use a simplier transmis­sion: simply it waits one clock without checking
the slave acknowledging, and sends the new
data.
This approach of course is less protected from
misworkingand decreasesthe noiseimmunity.

Figure 3: TimingDiagram of I2CBUS

2

Figure 4: Acknowledgeon the I

CBUS

5/10

TDA7435

SOFTWARESPECIFICATION
Interface Protocol

The interfaceprotocol comprises:

A start condition (s)

read/writetransmission)
A subaddressbyte.
A sequenceof data (N-bytes + acknowledge)
A stopcondition(P)

A chip address byte,(the LSB bit determines

CHIP ADDRESS SUBADDRESS DATA 1 toDATA n

MSB LSB MSB LSB MSB LSB

S1000101R/W

X X X I X A2A1A0

ACK

ACK

DATA

ACK = Acknowledge
S = Start
P = Stop
I = Auto Increment
X = Not used

MAX CLOCK SPEED500kbits/s

AUTO INCREMENT

If bit I in the subaddressbyte is setto ”1”, the autoincrementof the subaddressis enabled
SUBADDRESS (receivemode)

ACK

P

MSB LSB

X X X I X D2 D1 D0

0 0 0 Mux & Gain
0 0 1 Mute
0 1 0 Speaker Attenuator AUX 1 L
0 1 1 Speaker Attenuator AUX 1 R
1 0 0 High Pass FilterFL
1 0 1 High Pass FilterFR
1 1 0 High Pass FilterRL
1 1 1 High Pass FilterRR

TRANSMITTED DATA

Send Mode

MSB LSB

XXXXXSMXX

SM =Soft muteactivated(HIGHactive)
X = Not used

The transmitted data is automaticallyupdatedafter each ACK.
Transmissioncan be repeatedwithout new chipaddress.

FUNCTION

6/10

DATA BYTE SPECIFICATION
MUX & GAIN

TDA7435

MSB LSB

D7 D6 D5 D4 D3 D2 D1 D0

00000dB
00011dB
00102dB
00113dB
01004dB
01015dB
01106dB
01117dB
10008dB
10019dB
101010dB
101111dB
110012dB
110113dB
111014dB
111115dB

0 0 High Pass Filter Front
0 1 High Pass Filter Rear
1 0 Aux 2 Input
1 1 Mute

FUNCTION

AUX 1 InputGain

AUX 2 OutputSelection

Mute

MSB LSB

D7 D6 D5 D4 D3 D2 D1 D0

0 0 Soft mute - SLOW SLOPE
0 1 Soft mute - FAST SLOPE
0 Soft mute ON

1 Soft mute OFF
0 0 AUX 1 Input Mute Enabled
1 0 AUX 1 Input Mute Disabled

FUNCTION

7/10

TDA7435

Speaker

MSB LSB

D7 D6 D5 D4 D3 D2 D1 D0

0000dB
0 0 1 -1dB
0 1 0 -2dB
0 1 1 -3dB
1 0 0 -4dB
1 0 1 -5dB
1 1 0 -6dB
1 1 1 -7dB

0000 0dB
0001 -8dB
0010 -16dB
0011 -24dB
0100 -32dB
0101 -40dB
0110 -48dB
0111 -56dB
1000 -64dB
1001 -72dB
100
101
111

AUX 1 L, R

-1dB STEPS

-8dB STEPS

MUTE

HIGH PASSFILTERS

MSB LSB

D7 D6 D5 D4 D3 D2 D1 D0

0000 f
0001 f
0010 f
0011 f
0100 f
0101 f
0110 f
0111 f

1f

8/10

FL, FR, RL, RR

2nd order HP FilterMode
(C1 = C2 = 100nF)

= 40Hz

c

= 60Hz

c

= 80Hz

c

= 100Hz

c

= 120Hz

c

= 150Hz

c

= 180Hz

c

= 220Hz

c

First order HP Flat Mode

= 9Hz

c

SO28 PACKAGEMECHANICAL DATA

TDA7435

DIM.

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

A 2.65 0.104

a1 0.1 0.3 0.004 0.012

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 17.7 18.1 0.697 0.713

E 10 10.65 0.394 0.419
e 1.27 0.050

e3 16.51 0.65

F 7.4 7.6 0.291 0.299
L 0.4 1.27 0.016 0.050
S8

mm inch

(max.)

°

9/10

TDA7435

Purchaseof I2C Componentsof SGS-THOMSONMicrolectronics, conveys a licenseunderthe Philips

2

I

C Patent Rights to use these components in an I2C system, provided that the system conformsto

2

C StandardSpecificationsas definedby Philips.

the I

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rightsof third parties which may result from its use. No
license is grantedby implicationor otherwise under any patent or patentrights of SGS-THOMSON Microelectronics. Specification mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics productsare notauthorized for useas criticalcomponents in lifesupport devices or systemswithout express
written approval of SGS-THOMSON Microelectronics.

 1996 SGS-THOMSON Microelectronics – Printedin Italy – All Rights Reserved

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