max9758etjt Maxim Integrated Products, Inc., max9758etjt Datasheet - Page 17

• Manufacturer Part Number: max9758etjt
• Description: 2.3w Stereo Speaker Amplifiers And Directdrive Headphone Amplifiers With Automatic Level Control
• Manufacturer: Maxim Integrated Products, Inc.

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