
AS3515 V15
austriamicrosystems
Data Sheet, Confidential
www.austriamicrosystems.com
Revision 3.1
8
- 66
6 Detailed Functional Block Description
6.1
Line Output
6.1.1
General
The line output is designed to provide the audio signal with typical 1Vp at a load of minimum 10k
Ω, which is a minimum value for line
inputs. Additional this output amplifier is capable to drive a 32
Ω load (e.g. an earpiece of a mobile phone. To achieve this, the operation
mode can be switched from single ended stereo to mono differential.
This output stage has an independent gain regulation for left and right channel with 32 steps @ 1.5dB each. The gain can be set from –
40.5dB to +6dB.
Figure 2 Line Output Mode Block Diagrams
Stero Mode
Mono Differential Mode
Please observe that gain of upper amplifier needs to be
set to 0dB
6.1.2
Register Description
Enabling the output stage is done via a control bit in the audio settings register (AudioSet1 register 0x14h). The line out driver itself is
controlled by the following two registers.
Right Line Out Register (00h)
Table 4
LINE_OUT_R Register
Bit
Name
Default
Access
Description
7,6
reserved
00b
R/W
For testing purpose only, must be set to 0h
5
-
0b
R/W
not used
4..0
LOR_VOL
00000b
R/W
volume settings for right line output, adjustable in 32 steps @ 1.5dB
11111: 6 dB gain
11110: 4.5 dB gain
..
00001: -39 dB gain
00000: -40.5 dB gain
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