Ampro Corporation Single Board Computer Littleboard 550 User Manual
Page 60
Chapter 3
Hardware
54
Reference Manual
LittleBoard 550
Table 3-22. Audio Interface Pin/Signal Descriptions (J28)
Pin #
Signal
Description
1
VIDEO_L
Video audio signal in left channel
2
VIDEO_GND
Video digital ground (Audio ground)
3
VIDEO_R
Video audio signal in right channel
4
CD_L
CD-ROM signal left channel
5
CD_GND
CD-ROM digital ground (to Audio CODEC)
6
CD_R
CD-ROM signal right channel
7
LINE_IN_L
Line in signal left channel
8
LINE_IN_GND
Line in digital ground (Audio ground)
9
LINE_IN_R
Line in signal right channel
10
MIC1
Microphone in signal 1 or left channel
11
MIC_GND
Microphone digital ground (Audio ground)
12
MIC2
Microphone in signal 2 or right channel
13
MIC_REF
Microphone reference signal
14
NC/KEY
Not connected - Key pin
15
PHONE_IN
Phone signal in
16
PHONE_GND
Phone digital ground (Audio ground)
17
MONO_OUT
Monaural signal out
18
MONO_GND
Monaural digital ground (Audio ground)
19
+AOUT_L
+ Audio Amplifier output signal left channel
20
AGND
Audio Ground (-AOUT_L)
21
+AOUT_R
+ Audio Amplifier output signal right channel
22
AGND
Audio Ground (-AOUT_R)
23
AGND
Audio Ground
24
HP_L
Headphone signal left channel (from Audio Amp)
25
HP_R
Headphone signal right channel (from Audio Amp)
26
NC
Not connected (Headphone In)
Notes: The shaded area denotes power or ground.