Owner's manual

Shutdown (
SSHHDDNN
)
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)