In addition to the overload protection described

above, the device features a thermal shutdown

circuit which initially puts the device into a muting

state (@ Tj = 150

Tj = 160

Full protection against electrostatic discharges on

every pin is included.

3) Other Features

The device is provided with both stand-by and

mute functions, independently driven by two

CMOS logic compatible input pins.

The circuits dedicated to the switching on and off

of the amplifier have been carefully optimized to

avoid any kind of uncontrolled audible transient at

the output.

The sequence that we recommend during the

ON/OFF transients is shown by Figure 4.

The application of figure 5 shows the possibility of

using only one command for both st-by and mute

functions. On both the pins, the maximum appli-

cable range corresponds to the operating supply

voltage.

APPLICATION INFORMATION

HIGH-EFFICIENCY

Constraints of implementing high power solutions

are the power dissipation and the size of the

power supply. These are both due to the low effi-

ciency of conventional AB class amplifier ap-

proaches.

Here below (figure 6) is described a circuit pro-

posal for a high efficiency amplifier which can be

adopted for both HI-FI and CAR-RADIO applica-

tions.

1N4148

10K

30K

20K

10

µF

10

µF

MUTE

STBY

D93AU014

MUTE/

ST-BY

Figure 5: Single Signal ST-BY/MUTE Control

Circuit

PLAY

OFF

ST-BY

MUTE

MUTE

ST-BY

OFF

D98AU817

5V

5V

+Vs

(V)

+40

-40

VMUTE

PIN #10

(V)

VST-BY

PIN #9

(V)

-Vs

VIN

(mV)

IQ

(mA)

VOUT

(V)

Figure 4: Turn ON/OFF Suggested Sequence

TDA7293

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