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Advanced AC'97 Audio CODEC
General Description

The ALC202/ALC202A is an 18-bit, full duplex AC'97 2.2 compatible stereo audio CODEC designed for PC multimedia systems, including host/soft audio and AMR/CNR based designs. The ALC202 incorporates proprietary converter technology to achieve a high SNR, greater than 90 dB. The ALC202 AC'97 CODEC supports multiple CODEC extensions with independent variable sampling rates and built-in 3D effects. The ALC202 CODEC provides two pairs of stereo outputs with independent volume controls, a mono output, and multiple stereo and mono inputs, along with flexible mixing, gain and mute functions to provide a complete integrated audio solution for PCs. The digital interface circuitry of the ALC202 CODEC operates from a 5V/3.3V power supply with EAPD (External Amplifier Power Down) control for use in notebook and PC applications. The ALC202 integrates a 50mW/8W headset audio amplifier into the CODEC, saving BOM costs. The ALC202 also supports the SPDIF out function, which is compliant to AC'97 2.2, which can offer easy connection of PCs to consumer electronic products, such as AC3 decoder/speaker and mini disk devices. The ALC202 CODEC supports host/soft audio from Intel 810/815/820/845 chipsets as well as audio controller based VIA/SIS/ALI chipsets. Bundled Windows series drivers (Win95/98/ME/2000/XP/NT) and sound effect utilities (supporting Karaoke, emulation of 26 sound environments, 10-band equalizer) provide an excellent entertainment package for PC users. Finally, internal PLL circuits generate required timing signals, eliminating the need for external clocking devices. There are two differences between the ALC202 and the ALC202A. First, the ALC202 includes outputs for headphones with an op-amp, and in the ALC202A, those outputs are for True Line output and have no op-amp. Second, the Line Out channels on the ALC202 has no op-amp (1.0Vrms), where the ALC202A includes an op-amp (1.4Vrms).

  • Single-chip audio CODEC with high S/N ratio (>90 dB)
  • Compliant with AC'97 2.2 & WHQL specifications
  • Support of S/PDIF out is compliant with AC'97 rev2.2 specifications
  • Meets performance requirements for audio on PC2001 systems
  • Meets Microsoft PC99 & WLP 2.0 audio requirements
  • 18-bit Stereo full-duplex CODEC with independent and variable sampling rate
  • 18-bit ADC and 20-bit DAC resolution
  • Four analog line-level stereo inputs with 5-bit volume control: LINE_IN, CD, VIDEO, AUX
  • High quality differential CD input
  • Two analog line-level mono input: PC_BEEP, PHONE_IN
  • Supports double sampling rate (96KHz) of DVD audio playback
  • Two software selectable MIC inputs
  • +30dB boost preamplifier for MIC input
  • Stereo output with 6-bit volume control
  • Mono output with 5-bit volume control
  • Headphone output with 50mW/8W driving capability (ALC202)
  • Line output with 50mW/8W driving capability (ALC202A)
  • Headphone jack-detect function to mute LINE/MONO/HP output, and to control S/PDIF output
  • 3D stereo enhancement
  • Multiple CODEC extension capability
  • External Amplifier Power Down (EAPD) capability
  • High performance converter technology
  • Power management and enhanced power saving features
  • 2 GPIO pins
  • No external crystal/clock required
  • 14.318MHz/48MHza24.576MHz PLL saves crystal
  • DC voltage volume control
  • Auxiliary power (VAUX) to support Power Off CD function
  • Power support: digital: 3.3V; analog: 3.3V/5V
  • Standard 48-pin LQFP package
  • Multimedia PCs
  • 3D PC games
  • Information appliances (IA)
  • Voice recognition
  • Audio conferencing
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