C-28 Sun Ultra 60 Service Manual August 2001
C.1.13 Audio Card and Connector
The audio card provides various audio applications from telephone-quality speech
to CD-quality music. The audio card supports four jacks of identical type: line in,
line out, headphone out, and microphone in. TABLEC-6 lists the major features of the
audio card and FIGUREC-9 illustrates a functional block diagram.
Theaudio card connector is a dual-position, standard-edge connector whose features
include:
23 dual positions (46 total)
50-millimeter centerline
1.49 inches (total length)
TABLEC-6 Audio Card Features
Figure
Reference Feature Description
A Stereoline level Attenuated by a resistordivider network and
then fed into the Line Inputs of the Codec.
B Stereo microphone input Bufferedby a non-inverting operational
amplifier(one operational amplifier for the
left channel and oneoperational amplifier for
the right channel). The left and right outputs
arethen fed into the left and right Mic Inputs
of the Codec. A filtered+5 Vdc is fed to the
signal inputs.
C Internal CD-ROM
peripheral analog outputs Cabled to the motherboardand AC-coupled
tothe left and right Aux1 inputs of the Codec.
D Codex mono-output Fed into an active graphic equalizer to add
bass boost and mid-range attenuation.
Equalizer output is amplifiedand routed to
the frontmounted 16-ohm, 68-mm speaker.
E Line output A directoutput, except E1, which enables
muting of this signal. The mute function is
driven fromthe Codec PIO lines.
F Headphone output Buffered by an operational amplifierto give
headphone drive with low impedances of 16
ohms or more.Is independently mutable,
driven fromCodec PIO lines.
G MultiMedia Codec
(MMCodec) Heart of the audio module. A single-chip,
stereo,A/D and D/A converter based on
delta-sigma conversion.