MAX9708

20W/40W, Filterless, Spread-Spectrum,

Mono/Stereo, Class D Amplifier

10

Maxim Integrated

Typical Application Circuits/Functional Diagrams

OUTR+

OUTR-

OUTL-

OUTL+

SYNCIN

INL+

INL-

INR+

INR-

SHDN

G2

G1

SYNCOUT

PGND

RIN

RIN

RIN

RIN

VBIAS

VBIAS

TH0

TH1

TH2

TEMP

CPVDD

PVDD

PVDD

PVDD

PVDD

PVDD

VDD

VDD

C1P

C1N

REG

+

-

LEFT

CHANNEL

+

-

RIGHT

CHANNEL

VDIGITAL

C2

1

μF

C1

0.1

μF

0.1

μF

47

μF*

1

μF

1

μF

1

μF

1

μF

CREG

0.01

μF

CSS

0.47

μF

VDIGITAL

VDIGITAL

VDIGITAL

VDIGITAL

GND

MONO

FS1

FS2

RF

RF

RF

RF

10k

Ω

10k

Ω

14

13

17

16

27

26

30

28

29

18

35

34

33

32

19, 20, 21

8

9

10

51, 52

53, 54

45, 46

47, 48

11

22, 23

2–4, 39–41 49–50

5–7, 36–38

25

15

SS

24

MUTE

31

*ADDITIONAL BULK CAPACITANCE

CONFIGURATION: TQFN STEREO MODE, SSM, INTERNAL OSCILLATOR, GAIN = 22dB, THERMAL SETTING = +120

°C

MAX9708

GAIN

CONTROL

CONTROL

CHARGE

PUMP

REGULATOR

THERMAL SENSOR

MUX

CLASS D

MODULATOR

AND H-BRIDGE

CLASS D

MODULATOR

AND H-BRIDGE

Figure 1. Typical Application and Functional Diagram in Stereo Mode