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Table 4. volume control settings, Table 5. output mode control – Rainbow Electronics MAX9877 User Manual

Page 22

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Shutdown (S

SH

HD

DN

N)

1 = MAX9877 operational.

0 = MAX9877 in low-power shutdown mode.

SHDN is an active-low shutdown bit that overrides all
settings and places the entire device in low-power shut-
down mode. The I

2

C interface is fully active in this shut-

down mode and bypass mode remains operational. All
register settings are preserved while in shutdown.

MAX9877

Low RF Susceptibility, Mono Audio
Subsystem with DirectDrive Headphone Amplifier

22

______________________________________________________________________________________

Volume Control

The device has a separate volume control for left head-
phone, right headphone, and speaker amplifiers. The

total system gain is a combination of the input gain, the
volume control, and the output amplifier gain. Table 4
shows the volume settings for each volume control.

Table 4. Volume Control Settings

_VOL

CODE

B4

B3

B2

B1

B0

GAIN (dB)

0

0

0

0

0

0

MUTE

1

0

0

0

0

1

-75

2

0

0

0

1

0

-71

3

0

0

0

1

1

-67

4

0

0

1

0

0

-63

5

0

0

1

0

1

-59

6

0

0

1

1

0

-55

7

0

0

1

1

1

-51

8

0

1

0

0

0

-47

9

0

1

0

0

1

-44

10

0

1

0

1

0

-41

11

0

1

0

1

1

-38

12

0

1

1

0

0

-35

13

0

1

1

0

1

-32

14

0

1

1

1

0

-29

15

0

1

1

1

1

-26

_VOL

CODE

B4

B3

B2

B1

B0

GAIN (dB)

16

1

0

0

0

0

-23

17

1

0

0

0

1

-21

18

1

0

0

1

0

-19

19

1

0

0

1

1

-17

20

1

0

1

0

0

-15

21

1

0

1

0

1

-13

22

1

0

1

1

0

-11

23

1

0

1

1

1

-9

24

1

1

0

0

0

-7

25

1

1

0

0

1

-6

26

1

1

0

1

0

-5

27

1

1

0

1

1

-4

28

1

1

1

0

0

-3

29

1

1

1

0

1

-2

30

1

1

1

1

0

-1

31

1

1

1

1

1

0

Table 5. Output Mode Control

REGISTER

B7

B6

B5

B4

B3

B2

B1

B0

0x04

SHDN

BYPASS

OSC (Table 6 )

OUTMODE (Table 7)

Table 3. Speaker/Left Headphone/Right Headphone Volume Control

REGISTER

B7

B6

B5

B4

B3

B2

B1

B0

0x01

0

0

0

SVOL (Table 4)

0x02

0

0

0

HPLVOL (Table 4)

0x03

0

0

0

HPRVOL (Table 4)