Eurotech Appliances ZEUS PXA270 - Manual (Page 49)

ZEUS Technical Manual Detailed hardware description
© 2007 Eurotech Ltd Issue D 49
Audio
A Wolfson WM9712L AC’97 audio CODEC is used to support the audio features of the
ZEUS. Audio inputs supported by the WM9712L are stereo line in and a mono
microphone input.
The WM9712L provides a stereo line out that is amplified by a National Semiconductor
LM4880 250mW per channel power amplifier, suitable for driving an 8Ω load. The
WM9712L AC’97 codec may be turned off if it is not required. See the section Audio
power management , page 71 , for details.
Connection to the ZEUS audio features is via header J4.
See the section J4 – Audio connector , page 79 , for connector and mating connector
details. The table below shows pin assignments:
Function
Pin
Signal
Signal levels (max)
Frequency
response (Hz)
Microphone
10
9
7 MIC input
MIC voltage reference
output
Audio ground reference.
1Vrms 20 – 20k
Line in
1
5
3 Line input left
Line input right
Audio ground reference
1Vrms 20 – 20k
Line out
2
6
4 Line output left
Line output right
Audio ground reference
1Vrms 20 – 20k
Amp out
8
11
12 Amp output left
Amp output right
Audio ground reference 1.79V peak
1.26Vrms
(8Ω load) 223mW
20 – 20k