SGS-THOMSON Microelectronics TDA7266SA Service Manual

TDA7266SA

7W+7W DUAL BRIDGE AMPLIFIER

■ WIDE SUPPLY VOLTAGE RA NGE (3 .5 - 1 8 V)

■ MINIMUM EXTERNAL COMPONENTS

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

■ STAND-BY & MUTE FUNCTIONS

■ SHORT CIRCUIT PROTECTION

■ THERMAL OVERLOAD PROTECTION

DESCRIPTION

The TDA7266SA is a dual bridge amplifier specially
designed for LCD Monitor, PC Motherboard, TV and
Portable Radio applications.

BLOCK AND APPLICATION DIAGRAM

0.22µF

IN1

ST-BY 7

4

TECHNOLOGY BI20II

CLIPWATT15

ORDERING NUMBER: TDA7266SA

Pin to pin compatible with: TDA7266S, TDA7266,
TDA7266M, TDA7266MA, TDA7266B, TDA7297SA
& TDA7297.

V

CC

133

+

-

1

470µF 100nF

OUT1+

IN2

MUTE 6

September 2003

0.22µF

S-GND

PW-GND

9

12

8

Vref

OUT1-

15

14

2

OUT2+

OUT2-

D94AU175B

1/11

-

+

+

-

-

+

TDA7266SA

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

I

O

P

tot

T

op

T

stg, Tj

THERMAL DATA

Symbol Parameter Value Unit

R

th j-case

R

th j-amb

Supply Voltage 20 V

s

Output Peak Current (internally limited) 2 A
Total Power Dissipation (T

= 70°C) 20 W

amb

Operating Temperature 0 to 70 °C
Storage and Junction Temperature -40 to 150 °C

Thermal Resistance Junction-case Typ = 1.8; Max. = 2.5 °C/W
Thermal Resistance Junction-ambient 48 °C/W

PIN CONNECTION

ELECTRICAL CHARACTERISTCS

(V

= 11V, RL = 8Ω, f = 1KHz, T

CC

(Top view)

15
14
13
12
11
10

9
8
7
6
5
4
3
2
1

D03AU1463

= 25°C unless otherwise specified)

amb

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

CC

OUT1­OUT1+

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

V

P

THD Total Harmonic Distortion P

Supply Range 3 11 18 V

CC

I

Total Quiescent Current 50 65 mA

q

Output Offset Voltage 120 mV

OS

Output Power THD 10% 6.3 7 W

O

= 1W 0.05 0.2 %

O

= 0.1W to 2W

P

O

1%

f = 100Hz to 15KHz

SVR Supply Voltage Rejection f = 100Hz, VR =0.5V 40 56 dB

CT Crosstalk 46 60 dB

A

MUTE

∆G

T

G

Mute Attenuation 60 80 dB
Thermal Threshold 150 °C

w

Closed Loop Voltage Gain 25 26 27 dB

V

Voltage Gain Matching 0.5 dB

V

2/11

TDA7266SA

ELECTRICAL CHARACTERISTCS

(V

= 11V, RL = 8Ω, f = 1KHz, T

CC

(continued)

= 25°C unless otherwise specified)

amb

Symbol Parameter Test Condition Min. Typ. Max. Unit

R

Input Resistance 25 30 KΩ

i

VT

VT

I

MUTE

ST-BY

e

Mute Threshold for VCC > 6.4V; Vo = -30dB 2.3 2.9 4.1 V

< 6.4V; Vo = -30dB VCC/2-1VCC/2

for V

CC

-075

St-by Threshold 0.8 1.3 1.8 V

ST-BY

St-by Current V6 = GND 100 µA
Total Output Voltage A Curve; f = 20Hzto 20KHz 150 µV

N

VCC/2

-0.5

V

APPLICATION SUGGESTION

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 St­by and mute signals sequence. It is quite simple to obtain this function using a microprocessor (Fig. 1 and 2).

At first St-by signal (from

µ

P) goes high and the voltage across the St-by terminal (Pin 7) starts to increase ex­ponentially. The external RC network is intended to turn-on slowly the biasing circuits of 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, C53) 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.

Figure 1. Microprocessor Application

C1 0.22µF

IN1

R1 10K

ST-BY

C2

10µF

µP

IN2

MUTE

S-GND

C3 0.22µF

R2 10K

C4

1µF

PW-GND

V

CC

4

7

9

Vref

12

6

8

+

+

+

+

133

1

-

-

-

-

2

15

14

C5

470µFC6100nF

OUT1+

OUT1-

OUT2+

OUT2-

D95AU258A

3/11

TDA7266SA

Figure 2. Microprocessor Dri ving Sig nals

+VS(V)

V

IN

(mV)

V

ST-BY

pin 7

1.8

1.3

0.8

V

MUTE

pin 6

4.1

2.9

2.3

I

q

(mA)

V

OUT

(V)

OFF

ST-BY

PLAY MUTE ST-BY

MUTE

OFF

D96AU259mod

B) Low Cost Application

In low cost applications where the µP is not present, the suggested circuit is shown in fig.3.
The St-by and mute terminals are tied together and they are connected to the supply l ine via an external v oltage

divider.
The device is switched-on/off from the supply line and the external capacitor C4 is intended to delay the St-by

and mute threshold exceeding, avoiding "Popping" problems.

4/11