February 1995

4

Philips Semiconductors

Preliminary specification

2

× 24 W BTL or 4 × 12 W single-ended car

radio power amplifier

TDA8564Q

PINNING

SYMBOL

PIN

DESCRIPTION

−INV1

1

non-inverting input 1

SGND

2

signal ground

INV2

3

inverting 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

INV3

15

inverting input 3

16

diagnostic output

−INV4

17

non-inverting input 4

Fig.2 Pin configuration.

handbook, halfpage

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

TDA8564Q

INV1

SGND

INV2

SVRR

OUT1

GND1

OUT2

n.c.

OUT3

GND2

OUT4

V

MODE

INV3

DIAG

INV4

P2

V P1

MLC810

V

FUNCTIONAL DESCRIPTION

The TDA8564Q contains four identical amplifiers which

can be used for single-ended or bridge applications. The

gain of each amplifier is fixed at 40 dB (46 dB in BTL).

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

10 k

Ω

mode

select

switch

VP