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. TABLE C-6lists the major features of the

 

audio card and FIGURE C-9illustrates a functional block diagram.

 

TABLE C-6Audio Card Features

 

 

 

 

 

 

 

 

Figure

 

 

 

 

Reference

Feature

Description

 

 

 

 

 

 

A

Stereo line level

Attenuated by a resistor divider network and

 

 

 

then fed into the Line Inputs of the Codec.

 

B

Stereo microphone input

Buffered by a non-inverting operational

 

 

 

amplifier (one operational amplifier for the

 

 

 

left channel and one operational amplifier for

 

 

 

the right channel). The left and right outputs

 

 

 

are then 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

Cabled to the motherboard and AC-coupled

 

 

peripheral analog outputs

to the 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 amplified and routed to

 

 

 

the front mounted 16-ohm, 68-mm speaker.

 

E

Line output

A direct output, except E1, which enables

 

 

 

muting of this signal. The mute function is

 

 

 

driven from the Codec PIO lines.

 

F

Headphone output

Buffered by an operational amplifier to give

 

 

 

headphone drive with low impedances of 16

 

 

 

ohms or more. Is independently mutable,

 

 

 

driven from Codec PIO lines.

 

G

MultiMedia Codec

Heart of the audio module. A single-chip,

 

 

(MMCodec)

stereo, A/D and D/A converter based on

 

 

 

delta-sigma conversion.

 

 

 

 

 

The audio 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)

C-28Sun Ultra 60 Service Manual • August 2001

Page 228
Image 228
Sun Microsystems 60 service manual Audio Card and Connector, Table C-6Audio Card Features