Ampro LittleBoard 800, Reference Manual

Page: 59 / 96

Chapter 3 Hardware
LittleBoard 800 Reference Manual 53
Audio Interface (J9)
The audio solution on the LittleBoard 800 is provided by the Realtek ALC202A audio CODEC. The
chip is defined by AC97 and is revision 2.2 compliant. The audio interface signals are supplied to the
26-pin 2mm connector (J9). Refer to the following list for the
Audio CODEC (ALC202A) features.
•
Analog Mixer Dynamic Range 97dB (typ)
•
D/A Dynamic Range 89dB (typ) and A/D Dynamic Range 90dB (typ)
•
AC’97 Rev 2.1 compliant
•
High quality Sample Rate Conversion (SRC) from 4kHz to 48kHz
•
3D Sound circuitry and PC-Beep passthrough to Line Out while reset is held active low
•
True Line Level Output with volume control independent of Line Out
Table 3-22 describes the pin-outs and signals of the audio interface and it has 26 pins, 2 rows, odd/even,
(1, 2) with 2mm pin spacing.
Table 3-22. Audio Interface Pin/Signal Descriptions (J9)
Pin # Signal Description
1 VIDEO_L Video-Audio signal in left channel
2 VIDEO_GND Video Audio ground
3 VIDEO_R Video-Audio signal in right channel
4 CD_L CD-ROM signal left channel
5 CD_GND CD-ROM Audio ground
6 CD_R CD-ROM signal right channel
7 LINE_IN_L Line in signal left channel
8 LINE_IN_GND Line in Audio ground
9 LINE_IN_R Line in signal right channel
10 MIC1 Microphone in signal 1 or left channel
11 MIC_GND Microphone Audio ground
12 MIC2 Microphone in signal 2 or right channel
13 MIC_REF Microphone reference signal
14 NC/KEY Not Connected - Key
15 PHONE_IN Phone signal in
16 PHONE_GND Phone Audio ground
17 MONO_OUT Monaural signal out
18 MONO_GND Monaural Audio ground
19 +AOUT_L - Audio out signal left channel
20 -AOUT_L + Audio out Audio ground
21 +AOUT_R - Audio out signal right channel
22 -AOUT_R + Audio out Audio ground
23 GND Audio Ground (tied to all audio grounds)
24 HP_L Headphone signal left channel
25 HP_R Headphone signal right channel
26 NC Not Connected
Note: The shaded area denotes power or ground.