1995 Dec 08

4

Philips Semiconductors

Product specification

4

× 12 W single-ended car radio

power amplifier with diagnostic interface

TDA8565Q

PINNING

SYMBOL

PIN

DESCRIPTION

IN1

1

input 1

SGND

2

signal ground

IN2

3

input 2

SVRR

4

supply voltage ripple rejection

5

supply voltage 1

OUT1

6

output 1

GND1

7

power ground 1

OUT2

8

output 2

n.c.

9

not connected

OUT3

10

output 3

GND2

11

power ground 2

OUT4

12

output 4

13

supply voltage 2

MODE

14

mode select switch input

IN3

15

input 3

16

diagnostic output

IN4

17

input 4

Fig.2 Pin configuration.

dbook, halfpage

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

TDA8565Q

IN1

SGND

IN2

SVRR

OUT1

GND1

OUTP2

n.c.

OUT3

GND2

OUTP4

V

MODE

IN3

DIAG

IN4

P2

V P1

MLC393

V

FUNCTIONAL DESCRIPTION

The TDA8565Q contains four identical amplifiers which

can be used for single-ended applications. The gain of

each amplifier is fixed at 40 dB. Special features of the

device are as follows.

Mode select switch (pin 14)

• Low standby current (<100 µA)

• Low switching current (low cost supply switch)

• Mute facility.

To avoid switch-on plops, it is advised to keep the amplifier

in the mute mode during

≥100 ms (charging of the input

capacitors at pins 1, 3, 15 and 17).

This can be achieved by:

• Microcontroller control

• External timing circuit (see Fig.3).

The circuit in Fig.3 slowly ramps up the voltage at the

mode select switch pin when switching on and results in

fast muting when switching off.

In the event of fast switching at mode select pin it is

to 150

µF to avoid switch plops.

Fig.3 Mode select switch circuitry.

handbook, halfpage

100 k

Ω

MGA708

47

µF

10 k

Ω

100

Ω

mode

select

switch

VP