5

Application information

5.1

Application circuit

Figure 20. Application circuit

L+

R+

R-

VCC

GND

L+

L-

R+

R-

TDA7498L

MUTE

S TBY

3V3 P OWER S UP P LY

S ingle-Ended

*

*

*

*

*

Input

CLASS-D AMPLIFIER

*

*

*

*

S ingle-Ended

Input

Load=6 ohm

For

For

FREQUENCY S HIFT

OUTP UT

INP UT

L-

*

LC FILTER COMPONENT

Load

L1,L2,L3,L4

C20,C26 C18,C22,C24,C28

6 ohm

8 ohm

22 uH

22 uH

470 nF

680 nF

220 nF

220 nF

C5

100nF

R3

39K

L4

22uH

C1

1uF

C2

1uF

C11

1uF

C12

1uF

C8

100nF

C25

100nF

C19

100nF

C27

330pF

R6

22R

C40

220nF

C41

220nF

C21

330pF

R5

22R

C42

220nF

C43

220nF

C3

1nF

C4

1nF

C13

1nF

C14

1nF

32 INPB

36 VSS

9

OUTNB

5

P GNDB

7

PVCCB

3

OUTPB

10

OUTNA

12

PVCCA

14

P GNDA

16

OUTPA

33

INNB

8

OUTNB

4

P GNDB

21 MUTE

6

PVCCB

2

OUTPB

29

SVR

11

OUTNA

1

SUB_GND

22

INPA

23

INNA

27

S GND

26

VDDS

28

DIAG

19 VDDPW

18 PGND

20 STBY

24 ROSC

31 GAIN1

35

SVCC

30

GAIN0

25 SYNCLK

17

OUTPA

15

P GNDA

34

VREF

13

PVCCA

IC1

TDA7498L

R1

100k

R7

22R

C6

100nF

R4

120k

R2

33k

R8

6.8k

C26

680nF

C10

100nF

C20

680nF

J 6

J 5

2

1

3

S1

2

1

3

S2

C9

100nF

C29

2.2uF

2 GND

1

OUT

3

IN

IC2

L4931CZ33

+

C15

2.2uF

16V

1

2

J 2

J 8

J 7

+

C7

2.2uF

16V

+

C23

2200uF

50V

L3

22uH

L1

22uH

L2

22uH

C17

10uF

10V

C16

10uF

10V

D1

18V

1

2

3

Q1

R9

120K

J 4

C30

1uF

C31

1uF

R14 47k

R15

8R

C28

220nF

R16

8R

C24

220nF

R17

8R

C18

220nF

R18

8R

C22

220nF

SYNC

1

2

3

4

J 3

2

4

1

3

J 1

R13 68k

DIAG

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

S GND

VDDS

VDDS

VCC

S GND

S GND

S GND

S GND

S GND

S GND

3V3

3V3

S GND

S GND

S GND

S GND

S GND

S GND

S GND

FS

FS

FS

5.2

Mode selection

The three operating modes of the TDA7498L are set by the two inputs, STBY (pin 20) and MUTE (pin 21).

•

Standby mode: all circuits are turned off, very low current consumption.

•

Mute mode: inputs are connected to ground and the positive and negative PWM outputs are at 50% duty

cycle.

•

Play mode: the amplifiers are active.

The protection functions of the TDA7498L are enabled by pulling down the voltages of the STBY and MUTE

inputs shown in Figure 21. Standby and mute circuits. The input current of the corresponding pins must be limited

to 200 µA.

Table 6. Mode settings

Mode

STBY

MUTE

Standby

L (1)

X (don’t care)

Mute

H (1)

L

Play

H

H

1. Drive levels defined in Table 5. Electrical characteristics

TDA7498L

Application information

DS6539 - Rev 6

page 13/23