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5.6.9.3 Class-D Speaker Analog Output Volume Control
TSC2117
Low-Power Audio Codec With Embedded miniDSP, Stereo Class-D
Speaker Amplifier, and Smart Four-Wire Touch-Screen Controller
SLAS550A – APRIL 2009 – REVISED JUNE 2009
www.ti.com
Table 5-38. Analog Volume Control for Headphone and Speaker Outputs (for D7 = 1)
Analog
Register Value
Attenuation
Register Value
Attenuation
Register Value
Attenuation
Register Value
Attenuation
(dB)
0
0.0
30
–15.0
60
–30.1
90
–45.2
1
–0.5
31
–15.5
61
–30.6
91
–45.8
2
–1.0
32
–16.0
62
–31.1
92
–46.2
3
–1.5
33
–16.5
63
–31.6
93
–46.7
4
–2.0
34
–17.0
64
–32.1
94
–47.4
5
–2.5
35
–17.5
65
–32.6
95
–47.9
6
–3.0
36
–18.1
66
–33.1
96
–48.2
7
–3.5
37
–18.6
67
–33.6
97
–48.7
8
–4.0
38
–19.1
68
–34.1
98
–49.3
9
–4.5
39
–19.6
69
–34.6
99
–50.0
10
–5.0
40
–20.1
70
–35.2
100
–50.3
11
–5.5
41
–20.6
71
–35.7
101
–51.0
12
–6.0
42
–21.1
72
–36.2
102
–51.4
13
–6.5
43
–21.6
73
–36.7
103
–51.8
14
–7.0
44
–22.1
74
–37.2
104
–52.2
15
–7.5
45
–22.6
75
–37.7
105
–52.7
16
–8.0
46
–23.1
76
–38.2
106
–53.7
17
–8.5
47
–23.6
77
–38.7
107
–54.2
18
–9.0
48
–24.1
78
–39.2
108
–55.3
19
–9.5
49
–24.6
79
–39.7
109
–56.7
20
–10.0
50
–25.1
80
–40.2
110
–58.3
21
–10.5
51
–25.6
81
–40.7
111
–60.2
22
–11.0
52
–26.1
82
–41.2
112
–62.7
23
–11.5
53
–26.6
83
–41.7
113
–64.3
24
–12.0
54
–27.1
84
–42.1
114
–66.2
25
–12.5
55
–27.6
85
–42.7
115
–68.7
26
–13.0
56
–28.1
86
–43.2
116
–72.2
27
–13.5
57
–28.6
87
–43.8
117–127
–78.3
28
–14.0
58
–29.1
88
–44.3
29
–14.5
59
–29.6
89
–44.8
For the speaker outputs, the analog volume control has a range from 0 dB to –78 dB in 0.5-dB steps for
soft-stepping logic.
Routing the left-channel DAC output signal to the left-channel analog volume control is done by writing to
page 1/register 35, bit D6. Routing the right-channel DAC output signal to the right-channel analog volume
control is done by writing to page 1/register 35, bit D2. Changing the left-channel analog volume for the
speaker is controlled by writing to page 1/register 38, bits D6–D0. Changing the right-channel analog
volume for the speaker is controlled by writing to page 1/register 39, bits D6–D0.
Routing the signal from the output of the left-channel analog volume control to the input of the left-channel
speaker amplifier is done by writing to page 1/register 38, bit D7. Routing the signal from the output of the
right-channel analog volume control to the input of the right-channel speaker amplifier is done by writing to
page 1/register 39, bit D7.
The analog volume-control soft-stepping time is based on the setting in page 0/register 63, bits D1–D0.
APPLICATION INFORMATION
64