Philips TDA8568Q-N3, TDA8568Q-N2, TDA8568Q-N1 Datasheet

DATA SH EET

Product specification
Supersedes data of 1997 Feb 12
File under Integrated Circuits, IC01

1998 Sep 23

INTEGRATED CIRCUITS

TDA8568Q

4 × 25 W BTL quad car radio power
amplifier

1998 Sep 23 2

Philips Semiconductors Product specification

4 × 25 W BTL quad car radio power
amplifier

TDA8568Q

FEATURES

• Requires very few external components

• High output power

• Low output offset voltage

• Fixed gain

• Diagnostic facility (distortion, short-circuit and

temperature pre-warning)

• Good ripple rejection

• Mode select switch (operating, mute and standby)

• Load dump protection

• Short-circuit safe to ground and to V

P

and across the

load

• Low power dissipation in any short-circuit condition

• Thermally protected

• Reverse polarity safe

• Electrostatic discharge protection

• No switch-on/switch-off plop

• Flexible leads

• Low thermal resistance

• Pin compatible with the TDA8567Q, except for the gain.

GENERAL DESCRIPTION

The TDA8568Q is a integrated class-B output amplifier in
a 23-lead Single-In-Line (SIL) plastic power package.
It contains four amplifiers in BTL configuration, each with a
gain of 40 dB. The output power is 4 × 25 W in a 4 Ω load.

APPLICA TIONS

• The device is primarily developed for car radio
applications.

QUICK REFERENCE DATA

ORDERING INFORMATION

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

V

P

operating supply voltage 6 14.4 18 V

I

ORM

repetitive peak output current −−7.5 A

I

q(tot)

total quiescent current − 230 − mA

I

stb

standby current − 0.2 100 µA

I

sw

switch-on current −−80 µA

Z

i

 input impedance 25 30 − kΩ

P

o

output power THD = 10% − 25 − W

SVRR supply voltage ripple rejection R

s

=0Ω−45 − dB

α

cs

channel separation Rs=10kΩ−50 − dB

G

v

closed loop voltage gain 39 40 41 dB

V

n(o)

noise output voltage Rs=0Ω−−250 µV

∆V

O

 DC output offset voltage −−200 mV

TYPE

NUMBER

PACKAGE

NAME DESCRIPTION VERSION

TDA8568Q DBS23P plastic DIL-bent-SIL power package; 23 leads (straight lead length 3.2 mm) SOT411-1

1998 Sep 23 3

Philips Semiconductors Product specification

4 × 25 W BTL quad car radio power
amplifier

TDA8568Q

BLOCK DIAGRAM

Fig.1 Block diagram.

handbook, full pagewidth

MGG160

OUT1+

OUT1−

+

−

+

−

V

ref

2

IN1

IN2

4

23168115

10

MODE

V

P1

V

P2

V

P3

V

P4

211863

PGND1 PGND2 PGND3 PGND4

30 kΩ

OUT2+

OUT2−

+

−

+

−

7

5

11

30 kΩ

OUT3+

OUT3−

+

−

+

−

V

ref

17

IN3

SGND

TDA8568Q

IN4

19

13

12

30 kΩ

OUT4+

OUT4−

+

−

+

−

22

20

14

30 kΩ

V

DIAG

DIAGNOSTIC

9

1998 Sep 23 4

Philips Semiconductors Product specification

4 × 25 W BTL quad car radio power
amplifier

TDA8568Q

PINNING

SYMBOL PIN DESCRIPTION

V

P1

1 supply voltage 1
OUT1+ 2 output 1+
PGND1 3 power ground 1
OUT1− 4 output 1−
OUT2− 5 output 2−
PGND2 6 power ground 2
OUT2+ 7 output 2+
V

P2

8 supply voltage 2
V

DIAG

9 diagnostic output
IN1 10 input 1
IN2 11 input 2
SGND 12 signal ground
IN3 13 input 3
IN4 14 input 4
MODE 15 mode select switch input
V

P3

16 supply voltage 3
OUT3+ 17 output 3+
PGND3 18 power ground 3
OUT3− 19 output 3−
OUT4− 20 output 4−
PGND4 21 power ground 4
OUT4+ 22 output 4+
V

P4

23 supply voltage 4

handbook, halfpage

TDA8568Q

MGG159

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23

V

P1

OUT1+

PGND1

OUT1−
OUT2−

PGND2

OUT2+

V

P2

V

DIAG

IN1
IN2

SGND

IN3
IN4

MODE

V

P3

OUT3+

PGND3

OUT3−
OUT4−

PGND4

OUT4+

V

P4

Fig.2 Pin configuration.

1998 Sep 23 5

Philips Semiconductors Product specification

4 × 25 W BTL quad car radio power
amplifier

TDA8568Q

FUNCTIONAL DESCRIPTION

The TDA8568Q contains four identical amplifiers which
can be used for bridge applications. The gain of each
amplifier is fixed at 40 dB.

Mode select switch (pin 15)

• Standby: low supply current (<100 µA)

• Mute: input signal suppressed

• Operating: normal on condition.

Since this pin has a low input current (<80 µA), a low cost
supply switch can be applied.

To avoid switch-on plops, it is advised to keep the amplifier
in the mute mode during ≥150 ms (charging of the input
capacitors at pins 10, 11, 13 and 14). When switching
from standby to mute, the slope should be at least 18 V/s.

This can be realized by:

• Microprocessor control

• External timing circuit (see Fig.3).

Diagnostic output (pin 9)

D

YNAMIC DISTORTION DETECTOR (DDD)

At the onset of clipping of one or more output stages, the
dynamic distortion detector becomes active and pin 9
goes LOW. This information can be used to drive a sound
processor or DC volume control to attenuate the input
signal and so limit the distortion. The output level of pin 9
is independent of the number of channels that are clipping
(see Fig.4).

S

HORT-CIRCUIT DIAGNOSTIC

When a short-circuit occurs at one or more outputs to
ground or to the supply voltage, the output stages are
switched off until the short-circuit is removed and the
device is switched on again, with a delay of approximately
10 ms after removal of the short-circuit. During this
short-circuit condition, pin 9 is continuously LOW.

When a short-circuit occurs across the load of one or more
channels, the output stages are switched off during
approximately 10 ms. After that time it is checked during
approximately 50 µs to determine whether the short-circuit
is still present.
Due to this duty cycle of 50 µs/10 ms the average current
consumption during this short-circuit condition is very low.

During this short-circuit condition, pin 9 is LOW for 10 ms
and HIGH for 50 µs (see Fig.5). The protection circuits of
all channels are coupled. This means that if a short-circuit
condition occurs in one of the channels, all channels are
switched off. Consequently, the power dissipation in any
short-circuit condition is very low.

T

EMPERATURE PRE-WARNING

When the virtual junction temperature Tvj reaches 145 °C,
pin 9 goes LOW.

O

PEN COLLECTOR OUTPUTS

The diagnostic pin has an open collector output, so more
devices can be tied together. An external pull-up resistor is
needed.

Fig.3 Mode select switch circuitry.

handbook, halfpage

+V

P

MODE

MGD959

BZX79C/3.9V

10 kΩ

47 µF

Fig.4 Distortion detector waveform.

handbook, halfpage

V

9

0

V

P

V

o

0

t

MGG155

1998 Sep 23 6

Philips Semiconductors Product specification

4 × 25 W BTL quad car radio power
amplifier

TDA8568Q

Fig.5 Short-circuit waveform.

handbook, full pagewidth

MGG156

short-circuit over the load

10 ms

50 µs

t

t

V

P

short

circuit

current

V

9