Table 4. volume levels, Analog volume control (vol) – Rainbow Electronics MAX9758 User Manual
Page 17
Analog Volume Control (VOL)
The MAX9756/MAX9757/MAX9758 feature an analog
volume control that varies the gain of the device in 31
discrete steps based upon the DC voltage applied to
VOL (see Table 4). The input range of VOL is from 0
(full volume) to HPV
DD
(full mute), with example step
sizes shown in Table 3. Connect the reference of the
device driving VOL (Figure 7) to HPV
DD
. Connect VOL
to GND (full volume) if volume control is not used.
MAX9756/MAX9757/MAX9758
2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control
______________________________________________________________________________________
17
Table 4. Volume Levels
V
VOL
(V) = MULTIPLIER x
HPV
DD
SPEAKER MODE
GAIN (dB)
HEADPHONE MODE
GAIN (dB)
M U L TIPLIE R
V
VOL
(MIN)
*
V
VOL
(MAX)
*
GA I N 3 = 0
GA I N 2 = 0
GA I N 1 = 0
GA I N 3 = 0
GA I N 2 = 0
GA I N 1 = 1
GA I N 3 = 0
GA I N 2 = 1
GA I N 1 = 0
GA I N 3 = 0
GA I N 2 = 1
GA I N 1 = 1
GA I N 3 = 1
GA I N 2 = 0
GA I N 1 = 0
GA I N 3 = 1
GA I N 2 = 0
GA I N 1 = 1
GA I N 3 = 1
GA I N 2 = 1
GA I N 1 = 0
GA I N 3 = 1
GA I N 2 = 1
GA I N 1 = 1
GA I N 3 = X
GA I N 2 = 0
GA I N 1 = X
GA I N 3 = X
GA I N 2 = 1
GA I N 1 = X
0.07
0.00
0.49
15
16.5
18
19.5
21
22.5
24
25.5
0
3
0.16
0.49
0.57
14
16
17.5
19
20
22
23.5
25
-1
2.5
0.18
0.57
0.64
13
15
17
18.5
19
21
23
24.5
-2
2
0.21
0.64
0.72
12
14
16.5
18
18
20
22.5
24
-3
1.5
0.23
0.72
0.80
10
13
16
17.5
16
19
22
23.5
-5
1
0.25
0.80
0.88
8
12
15
17
14
18
21
23
-7
0
0.28
0.88
0.95
6
10
14
16.5
12
16
20
22.5
-9
-1
0.30
0.95
1.03
4
8
13
16
10
14
19
22
-11
-2
0.32
1.03
1.11
2
6
12
15
8
12
18
21
-13
-3
0.35
1.11
1.19
0
4
10
14
6
10
16
20
-15
-5
0.37
1.19
1.26
-2
2
8
13
4
8
14
19
-17
-7
0.39
1.26
1.34
-4
0
6
12
2
6
12
18
-19
-9
0.42
1.34
1.42
-6
-2
4
10
0
4
10
16
-21
-11
0.44
1.42
1.50
-8
-4
2
8
-2
2
8
14
-23
-13
0.46
1.50
1.57
-10
-6
0
6
-4
0
6
12
-25
-15
0.49
1.57
1.65
-12
-8
-2
4
-6
-2
4
10
-27
-17
0.51
1.65
1.73
-14
-10
-4
2
-8
-4
2
8
-29
-19
0.54
1.73
1.80
-16
-12
-6
0
-10
-6
0
6
-31
-21
0.56
1.80
1.88
-18
-14
-8
-2
-12
-8
-2
4
-33
-23
0.58
1.88
1.96
-20
-16
-10
-4
-14
-10
-4
2
-35
-25
0.61
1.96
2.04
-22
-18
-12
-6
-16
-12
-6
0
-37
-27
0.63
2.04
2.11
-24
-20
-14
-8
-18
-14
-8
-2
-39
-29
0.65
2.11
2.19
-26
-22
-16
-10
-20
-16
-10
-4
-41
-31
0.68
2.19
2.27
-28
-24
-18
-12
-22
-18
-12
-6
-43
-33
0.70
2.27
2.35
-32
-26
-20
-14
-26
-20
-14
-8
-47
-35
0.72
2.35
2.42
-36
-28
-22
-16
-30
-22
-16
-10
-51
-37
0.75
2.42
2.50
-40
-32
-24
-18
-34
-26
-18
-12
-55
-39
0.77
2.50
2.58
-44
-36
-26
-20
-38
-30
-20
-14
-59
-41
0.79
2.58
2.66
-48
-40
-28
-22
-42
-34
-22
-15
-63
-43
0.82
2.66
2.73
-52
-44
-32
-24
-46
-38
-26
-18
-67
-47
0.84
2.73
2.81
-56
-48
-36
-26
-50
-42
-30
-20
-71
-51
0.93
2.81
3.30
MUTE
MUTE
MUTE
MUTE
MUTE
MUTE
MUTE
MUTE
MUTE
MUTE
MAX9756
V
REF
DAC
HPV
DD
VOL
Figure 7. Volume Control Circuit
*Based on HPV
DD
= 3.3V.
X = Don’t care.