Output Stage Volume Controls
www.ti.com ........................................................................................................................................... SLAS480B – JANUARY 2006 – REVISED DECEMBER 2008
Page 0 / Register 43:
Left DAC Digital Volume Control Register
BIT
READ/
RESET
DESCRIPTION
WRITE
VALUE
D7
R/W
1
Left DAC Digital Mute
0: The left DAC channel is not muted
1: The left DAC channel is muted
D6–D0
R/W
0000000
Left DAC Digital Volume Control Setting
0000000: Gain = 0.0-dB
0000001: Gain = –0.5-dB
0000010: Gain = –1.0-dB
…
1111101: Gain = –62.5-dB
1111110: Gain = –63.0-dB
1111111: Gain = –63.5-dB
Page 0 / Register 44:
Right DAC Digital Volume Control Register
BIT
READ/
RESET
DESCRIPTION
WRITE
VALUE
D7
R/W
1
Right DAC Digital Mute
0: The right DAC channel is not muted
1: The right DAC channel is muted
D6–D0
R/W
0000000
Right DAC Digital Volume Control Setting
0000000: Gain = 0.0-dB
0000001: Gain = –0.5-dB
0000010: Gain = –1.0-dB
…
1111101: Gain = –62.5-dB
1111110: Gain = –63.0-dB
1111111: Gain = –63.5-dB
A basic analog volume control with range from 0 dB to -78 dB and mute is replicated multiple times in the output
stage network, connected to each of the analog signals that route to the output stage. In addition, to enable
completely independent mixing operations to be performed for each output driver, each analog signal coming into
the output stage may have up to seven separate volume controls. These volume controls all have approximately
0.5-dB step programmability over most of the gain range, with steps increasing slightly at the lowest attenuations.
Table 4 lists the detailed gain versus programmed setting for this basic volume control.
Table 4. Output Stage Volume Control Settings and Gains
Gain Setting
Analog Gain
Gain Setting
Analog Gain
Gain Setting
Analog Gain
Gain Setting
Analog Gain
(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
-18.0
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
-35.1
100
-50.3
11
-5.5
41
-20.6
71
-35.7
101
-51.0
12
-6.0
42
-21.1
72
-36.1
102
-51.4
13
-6.5
43
-21.6
73
-36.7
103
-51.8
14
-7.0
44
-22.1
74
-37.1
104
-52.2
Copyright 2006–2008, Texas Instruments Incorporated
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