1997 Jul 15

4

Philips Semiconductors

Product specification

Stereo BTL audio output amplifier with DC

volume control

TDA7053A

PINNING

SYMBOL

PIN

DESCRIPTION

n.c.

1

not connected

VC1

2

DC volume control 1

n.c.

3

not connected

4

voltage input 1

5

positive supply voltage

6

voltage input 2

SGND

7

signal ground

VC2

8

DC volume control 2

OUT2+

9

positive output 2

PGND2

10

power ground 2

n.c.

11

not connected

OUT2

−

12

negative output 2

OUT1

−

13

negative output 1

PGND1

14

power ground 1

n.c.

15

not connected

OUT1+

16

positive output 1

Fig.2 Pin configuration.

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

VC1

n.c.

VP

I (1)

V

I (2)

V

SGND

VC2

OUT1

PGND1

PGND2

OUT1

OUT2

OUT2

n.c.

TDA7053A

TDA7053AT

n.c.

n.c.

MSA719 - 2

FUNCTIONAL DESCRIPTION

The TDA7053A and TDA7053AT are stereo output

amplifiers with two DC volume control stages, designed for

TV and monitors, but also suitable for battery-fed portable

recorders and radios.

In conventional DC volume control circuits the control or

input stage is AC coupled to the output stage via external

capacitors to keep the offset voltage low.

The two DC volume control stages are integrated into the

input stages so that no coupling capacitors are required

and a low offset voltage is still maintained. The minimum

supply voltage also remains low.

The BTL principle offers the following advantages:

• Lower peak value of the supply current

• The frequency of the ripple on the supply voltage is twice

the signal frequency.

Consequently, a reduced power supply with smaller

capacitors can be used which results in cost reductions.

For portable applications there is a trend to decrease the

supply voltage, resulting in a reduction of output power at

conventional output stages. Using the BTL principle

increases the output power.

The maximum gain of the amplifier is fixed at 40.5 dB.

The DC volume control stages have a logarithmic control

characteristic. Therefore, the total gain can be controlled

from +40.5 to

−33 dB.

If the DC volume control voltage falls below 0.4 V, the

device will switch to the mute mode.

across the load. A thermal protection circuit is also

implemented. If the crystal temperature rises above

150

°C the gain will be reduced, thereby reducing the

output power.

Special attention is given to switch-on and switch-off

clicks, low HF radiation and a good overall stability.