ST TDA7297 User Manual

®

TDA7297

15+15W DUAL BRIDGE AMPLIFIER

WIDE SUPPLY VOLTAGE RANGE (6V -18V)
MINIMUM EXTERNAL COMPONENTS

– NO SVR CAPACITOR
– NO BOOTSTRAP
– NO BOUCHEROT CELLS
– INTERNALLY FIXED GAIN

STAND-BY & MUTE FUNCTIONS
SHORT CIRCUIT PROTECTION
THERMAL OVERLOAD PROTECTION

DESCRIPTION

The TDA7297 is a dual bridge amplifier specially
designed for TV and Portable Radio applications.

BLOCK AND APPLICATION DIAGRAM

0.22µF

IN1

ST-BY 7

4

TECHNOLOGY BI20II

Multiwatt 15

ORDERING NUMBER:

V

CC

133

+

-

1

470µF 100nF

OUT1+

TDA7297

IN2

MUTE 6

September 2003

0.22µF

S-GND

PW-GND

9

12

8

Vref

OUT1-

15

14

2

OUT2+

OUT2-

D94AU175B

1/9

-

+

+

-

-

+

TDA7297

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

I
P
T

T

stg

THERMAL DATA

Symbol Description Value Unit

R

th j-case

Supply Voltage 20 V

S

Output Peak Current (internally limited) 2 A

O

Total Power Dissipation (T

tot

Operating Temperature 0 to 70 °C

op

= 70°C) 33 W

case

, TjStorage and Junction Temperature -40 to +150 °C

Thermal Resistance Junction to case Typ. 1.4 Max. 2 °C/W

PIN CONNECTION

ELECTRICAL CHARACTERISTICS

(Top view)

15
14
13
12
11
10

9
8
7
6
5
4
3
2
1

= 16.5V, RL = 8Ω, f = 1kHz, T

(V

CC

D95AU261

OUT2+
OUT2­VCC
IN2
N.C.
N.C.
S-GND
PW-GND
ST-BY
MUTE
N.C.
IN1
V

CC

OUT1­OUT1+

amb

= 25°C unless otherwise

specified.)

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

CC

I

q

V

OS

P

O

THD Total Harmonic Distortion P

SVR Supply Voltage Rejection f = 100Hz V

CT Crosstalk 46 60 dB

A

MUTE

T

W

G

V

∆Gv Voltage Gain Matching 0.5 dB

R

Supply Range 6.5 18 V
Total Quiescent Current RL = ∞ 50 65 mA
Output Offset Voltage 120 mV
Output Power THD = 10% 13 15 W

= 1W 0.1 0.3 %

O

P

= 0.1W to 5W

O

1%

f = 100Hz to 15kHz

= 0.5V 40 56 dB

R

Mute Attenuation 60 80 dB
Thermal Threshold 150 °C
Closed Loop Voltage Gain 31 32 33 dB

Input Resistance 25 30 KΩ

i

2/9

TDA7297

ELECTRICAL CHARACTERISTICS

Symbol Parameter Test Condition Min. Typ. Max. Unit

VT
VT

MUTE

ST-BY

I

ST-BY

e

N

Mute Threshold VO = -30dB 2.3 2.9 4.1 V
St-by Threshold 0.8 1.3 1.8 V
ST-BY current V6 = GND 100 µA
Total Output Noise Voltage A curve

APPLICATION SUGGES TION

STAND-BY AND MUTE FUNCTIONS

(A) Microprocessor Application

In order to avoid annoying "Pop-Noise" during
Turn-On/Off transients, it is necessary to guaran­tee the right St-by and mute signals sequence.
It is quite simple to obtain this function using a mi­croprocessor (Fig. 1 and 2).

At first St-by signal (f rom mP) goes high and the
voltage across the St-by terminal (Pin 7) starts t o
increase exponentially. The external RC network
is intended to turn-on slowly the biasing circuits of

Figure 1:

Microprocessor Application

(Continued)

f = 20Hz to 20kHz

150
220 500

the amplifier, this to avoid "POP" and "CLICK" on
the outputs.

When this voltage reaches the St-by threshold
level, the amplifier is switched-on and the external
capacitors in series to the input terminals (C3,
C5) start to charge.

It’s necessary to mantain the mute signal low until
the capacitors are fully charged, this to avoid that
the device goes in play mode causing a loud "Pop
Noise" on the speakers.

A delay of 100-200ms between St-by and mute
signals is suitable for a proper operation.

V

CC

µV
µV

µP

IN1

ST-BY

IN2

MUTE

C1 0.22µF

R1 10K

C2

10µF

C3 0.22µF

R2 10K

C4

1µF

PW-GND

S-GND

4

7

9

12

6

8

Vref

133

15

14

1

OUT1+

OUT1-

2

OUT2+

OUT2-

+

-

-

+

+

-

-

+

C5

470µF

D95AU258A

C6

100nF

3/9