Philips TDA7056AT User Manual

DATA SH EET

INTEGRATED CIRCUITS

TDA7056AT

3 W mono BTL audio amplifier with
DC volume control

Product specification 1998 Feb 23

NXP Semiconductors Product specification

3 W mono BTL audio amplifier with DC

TDA7056AT

volume control

FEATURES

• DC volume control

• Few external components

• Mute mode

• Thermal protection

• Short-circuit proof

• No switch-on or switch-off clicks

• Good overall stability

• Low power consumption

• Low HF radiation

• ESD protected on all pins.

QUICK REFERENCE DATA

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

V

P

P

o

G

v(max)

ΔG

v

I

q(tot)

THD total harmonic distortion P

supply voltage 4.5 − 18 V
output power VP=12V; RL=16Ω 33.5− W
maximum total voltage gain VP=12V; RL=16Ω 34.5 35.5 36.5 dB
voltage gain control range 75 80 − dB
total quiescent current VP=12V; RL= ∞− 816mA

GENERAL DESCRIPTION

The TDA7056AT is a mono Bridge-Tied Load (BTL) output
amplifier with DC volume control. It is designed for use in
TVs and monitors, but is also suitable for battery-fed
portable recorders and radios. The device is contained in
a 20-lead small outline package.

A Missing Current Limiter (MCL) is built in. The MCL circuit
is activated when the difference in current between the
output terminal of each amplifier exceeds 100 mA
(300 mA typ.). This level of 100 mA allows for
Single-Ended (SE) headphone applications.

=0.5W − 0.3 1 %

o

ORDERING INFORMATION

TYPE

NUMBER

TDA7056AT SO2 0 plastic small outline package with 20 leads; body width 7.5 mm SOT163-1

NAME DESCRIPTION VERSION

PACKAGE

1998 Feb 23 2

NXP Semiconductors Product specification

3 W mono BTL audio amplifier with DC
volume control

BLOCK DIAGRAM

handbook, full pagewidth

positive input

DC volume control

5

7

n.c.

1 to 3, 8 to 13,
16, 18 to 20

TDA7056AT

+

V

STABILIZER

ref

+

−

TEMPERATURE

PROTECTION

V

P

4

I + i

TDA7056AT

+

14

17I − i

positive output

−

negative output

ground

Fig.1 Block diagram.

signal

power

ground

15

MGM576

6

1998 Feb 23 3

NXP Semiconductors Product specification

3 W mono BTL audio amplifier with DC
volume control

PINNING

SYMBOL PIN DESCRIPTION

n.c. 1 not connected
n.c. 2 not connected
n.c. 3 not connected
V

P

V

I

GND1 6 signal ground
VC 7 DC volume control
n.c. 8 not connected
n.c. 9 not connected
n.c. 10 not connected
n.c. 11 not connected
n.c. 12 not connected
n.c. 13 not connected
OUT+ 14 positive output
GND2 15 power ground
n.c. 16 not connected
OUT− 17 negative output
n.c. 18 not connected
n.c. 19 not connected
n.c. 20 not connected

4 positive supply voltage
5 positive input

handbook, halfpage

n.c.

1

n.c.

2

n.c.

3

V

4

P

V

5

I

VC
n.c.
n.c.
n.c.

TDA7056AT

6
7
8
9

10

MGM577

GND1

Fig.2 Pin configuration.

TDA7056AT

n.c.

20
19

n.c.

18

n.c.

17

OUT−

16

n.c.
GND2

15

OUT+

14

n.c.

13

n.c.

12

n.c.

11

1998 Feb 23 4

NXP Semiconductors Product specification

3 W mono BTL audio amplifier with DC
volume control

FUNCTIONAL DESCRIPTION

The TDA7056AT is a mono BTL output amplifier with DC
volume control. It is designed for use in TVs and monitors
but is also suitable for battery-fed portable recorders and
radios.

In conventional DC volume circuits the control or input
stage is AC-coupled to the output stage via external
capacitors to keep the offset voltage low. In the
TDA7056AT the DC volume control stage is integrated into
the input stage so that no coupling capacitors ar e required.
With this configuration, a low offset voltage is still
maintained and the minimum supply voltage remains low.

The BTL principle offers the following advantages:

• Lower peak value of the supply current

• The frequency of the ripple on the supp ly voltage is twice

the signal frequency.

Consequently, a reduced power supply with smaller
capacitors can be used which also results in cost
reductions. For portable applications th er e is a tre nd to
decrease the supply voltage, resulting in a reduction of
output power at conventional output stages. Using the BTL
principle increases the output power.

TDA7056AT

The maximum gain of the amplifier is fixed at 35.5 dB.
The DC volume control stage has a logarithmic control
characteristic.

The total gain can be controlled from +35.5 to −44 dB.
If the DC volume control voltage is below 0.3 V, the device

switches to the mute mode.
The amplifier is short-circuit proof to ground, V

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.

Power dissipation

Assume V

=12V; RL=16Ω.

P

The maximum sine wave dissipation is 1.8 W.
The R

Therefore T

of the package is 60 K/W.

th vj-a

amb(max)

=150− 60 × 1.8 = 42 °C.

and

P

LIMITING VALUES

In accordance with the Absolu te Maximum Rating System (IEC 134 ) .

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

V
V
I

ORM

I

OSM

P
T

amb

T

stg

T

vj

t

sc

P
5, 7

tot

supply voltage − 18 V
input voltage pins 5 a nd 7 − 5V
repetitive peak output current − 1.25 A
non-repetitive peak output current − 1.5 A
total power dissipation T

< 60 °C − 1.5 W

case

operating ambient temperature −40 +85 °C
storage temperature −55 +150 °C
virtual junction temperature − 150 °C
short-circuit time − 1h

THERMAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS VALUE UNIT

R

th(j-a)

thermal resistance from junction to ambient in free air 60 K/W

1998 Feb 23 5

NXP Semiconductors Product specification

3 W mono BTL audio amplifier with DC

TDA7056AT

volume control

CHARACTERISTICS

=12V; VDC= 1.4 V; f = 1 kHz; RL=16Ω; T

V

P

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

Supply

V

P

I

q(tot)

Maximum gain (V

P

o

supply voltage 4.5 − 18 V
total quiescent current RL= ∞; note 1 − 816mA

=1.4V)

7

output power THD = 10%; RL=16Ω 33.5 − W
THD total harmonic distortion P
G

v(max)

V

i(rms)

V

n(o)(rms)

maximum total voltage gain 34.5 35.5 36.5 dB

input signal handling (RMS value) VVC=0.8V; THD< 1% 0.5 0.65 − V

noise output voltage (RMS value) f = 500 kHz; note 2 − 210 −μV
B bandwidth at −1dB − 0.02 to 300 − kHz
SVRR supply voltage ripple rejection note 3 38 46 − dB

⎪ DC output offset voltage ⎪V17− v14⎪−0 150 mV

⎪ΔV

OS

Z

i

Minimum gain (V

G

v

V

o(n)(rms)

input impedance (pin 3) 15 20 25 kΩ

=0.5V)

7

voltage gain −−44 − dB

noise output voltage (RMS value) note 4 − 20 30 μV

Mute position

V

o(mute)

output voltage in mute position VVC≤ 0.3 V;

DC volume control

ΔG
I

VC

v

voltage gain control range 75 80 − dB

control current VVC=0V 60 70 80 μA

=25°C; unless otherwise specified (see Fig.14).

amb

=0.5W − 0.3 1 %

o

− 35 45 μV

= 600 mV; note 4

V

I

Notes

1. With a load connected to the outputs the quiescent current will increase, the maximum value of this increase being
equal to the DC output offset voltage divided by R

2. The noise output voltage (V

3. The ripple rejection is measured with R

) at f = 500 kHz, is measured with Rs=0Ω and B = 5 kHz.

n(o)(rms)

s

=0Ω and f = 100 Hz to 10 kHz. The ripple voltage (V

.

L

=200mVRMS)

ripple

is applied to the positive supply rail.

4. The noise output voltage (V

) is measured with Rs=5kΩ unweighted.

n(o)(rms)

1998 Feb 23 6