Avalue EPI-LX800 - Manual (Page 20)

EPI-LX800 Series
20 EPI-LX800 Series User’s Manual
1.6.3 Realtek ALC203 Audio Codec
The ALC203 is a 20-bit DAC and 18-bit ADC full-duplex AC'97 2.3 compatible stereo audio
CODEC designed for PC multimedia systems, including host/soft audio, and AMR/CNR
based designs.
The ALC203 incorporates proprietary converter technology to achieve a high SNR (greater
than 100 dB), sensing logics for device reporting, and a Universal Audio Jack® for
improved user convenience. The ALC203 AC'97 CODEC supports multiple CODEC
extensions with independent variable sampling rates and built-in 3D effects. The ALC203
CODEC provides two pairs of stereo outputs with independent volume controls, a mono
output, multiple stereo and mono inputs, along with flexible mixing, gain, and mute
functions to provide a complete integrated audio solution for PCs.
The circuitry of the ALC203 CODEC operates from a 3.3V digital and 3.3V/5V analog
power supply with EAPD (External Amplifier Power Down) control for use in notebook and
PC applications. The ALC203 integrates a 50mW/20Ohm headset audio amplifier into the
CODEC, saving BOM costs. The ALC203 also supports the S/PDIF out function (complies
with AC'97 2.3) that offers easy connection of PCs to consumer electronic products, such
as AC3 decoders/speakers and mini disk devices.
The ALC203 CODEC supports host/soft audio from Intel ICHx chipsets as well as audio
controller based VIA/SIS/ALI/AMD/nVIDIA/ATI chipsets. Bundled Windows series drivers
(Win98/ME/NT/2000/XP, EAX/Direct Sound 3D/I3DL2/A3D compatible sound effect utilities
(supporting Karaoke, 26-kinds of environment sound emulation, 10-band equalizer), HRTF
3D positional audio and Sensaura™ 3D (optional) provide an excellent entertainment
package and game experience for PC users. An internal 14.318MHz -> 24.576MHz PLL
circuit generates required timing signals, eliminating the need for external crystal, whilst a
built-in PCBEEP generator removes the need for an external buzzer.