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

Mono/Stereo, Class D Amplifier

10

______________________________________________________________________________________

Typical Application Circuits/Functional Diagrams

OUTR+

OUTR-

OUTL-

OUTL+

SYNCIN

INL+

INL-

INR+

INR-

SHDN

G2

G1

SYNCOUT

PGND

TH0

TH1

TH2

TEMP

C1P

C1N

REG

+

-

LEFT

CHANNEL

+

-

RIGHT

CHANNEL

C2

1

µF

C1

0.1

µF

0.1

µF

47

µF*

1

µF

1

µF

1

µF

1

µF

0.01

µF

0.47

µF

GND

MONO

FS1

FS2

10k

Ω

10k

Ω

14 (15)

13 (14)

17 (20)

16 (19)

27 (30)

26 (29)

30 (35)

28 (31)

29 (34)

18 (21)

35 (40)

34 (39)

33 (38)

32 (37)

19, 20, 21 (22, 23, 24)

8 (9)

9 (10)

10 (11)

51, 52 (59, 60)

53, 54 (61, 62)

45, 46 (51, 52)

47, 48 (53, 54)

11 (12)

22, 23

(25, 26)

2–4, 39–41 49–50

(2–4, 45–47, 56–57)

5–7, 36–38

(5–7, 42-44)

25 (28)

15 (18)

SS

24 (27)

MUTE

31 (36)

( ) TQFP PACKAGE

*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