[Realtek Semiconductor Corp.]

General Description
The ALC250 is a 20-bit DAC and 18-bit ADC full duplex AC97 2.3 compatible stereo audio CODEC designed for PC multimedia systems, including host/soft audio and AMR/CNR based designs. The ALC250 incorporates proprietary converter technology to achieve a high SNR, greater than 100 dB, sensing logics for device reporting and Universal Audio Jack® to improve user interface. The ALC250 AC97 CODEC supports multiple CODEC extensions with independent variable sampling rates and built-in 3D effects. The ALC250 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 circuitry of the ALC250 CODEC operates from a +3.3V digital power and +5V analog power supply with EAPD (External Amplifier Power Down) control for use in notebook and PC applications. The ALC250 integrates a 50mW/20Ω headset audio amplifier into the CODEC, saving BOM costs. The ALC250 also supports the SPDIF out function, which is compliant to AC97 2.3, which can offer easy connection of PCs to consumer electronic products, such as AC3 decoder/speaker and mini disk devices. The ALC250 CODEC supports host/soft audio from Intel ICHx chipsets as well as audio controller based VIA/SIS/ALI/AMD/nVIDIA/ ATI chipset.

FEATUREs
● Built- in 7 Bands of Digital Hardware Equalizer for Optimizing Speaker Response
● Single chip with high S/N ratio (>100 dB)
● Meets performance requirements for audio on PC99/2001 systems
● Meets Microsoft WHQL/WLP 2.0 audio requirements
● 20-bit DAC and 18-bit ADC resolution
● Compliant with AC’97 2.3 specifications
   -LINE/HP-OUT, MIC-IN and LINE-IN sensing
   -14.318MHz-Æ24.576MHz PLL saves crystal
   -12.288MHz BITCLK input can be consumed
   -Integrated PCBEEP generator to save buzzer
   -Interrupt capability
   -Page registers and Analog Plug&Play
● Support of S/PDIF out is fully compliant with AC’97 rev2.3 specifications
● Three analog line-level stereo inputs with 5-bit volume control: LINE_IN, CD, AUX
● High quality differential CD input
● Two analog line-level mono input: PCBEEP, PHONE-IN
● Supports double sampling rate (96KHz) of DVD audio playback
● Two software selectable MIC inputs
● +6/12/20/30dB boost preamplifier for MIC input
● Stereo output with 6-bit volume control
● Mono output with 5-bit volume control
● Headphone output with 50mW/20Ω amplifier
● 3D Stereo Enhancement
● Multiple CODEC extension capability
● External Amplifier Power Down (EAPD) capability
● Power management and enhanced power saving features
● Stereo MIC record for AEC/BF application
● DC Voltage volume control
● Auxiliary power to support Power Off CD
● Adjustable VREFOUT control
● EQ operation can be controlled by 2 pins of serial bus
● 2 Universal Audio Jack (UAJ)® for front panel
● Support 32K/44.1K/48K/96KHz of S/PDIF output
● Support 32K/44.1K/48KHz of S/PDIF input
● Power support: Digital: 3.3V; Analog: 3.3V/5V
● Standard 48-Pin LQFP Package
● EAX™ 1.0&2.0 compatible
● Direct Sound 3D™ compatible
● A3D™ compatible
● I3DL2 compatible
● HRTF 3D Positional Audio
● Sensaura™ 3D Enhancement (optional)
● 10 Bands of Software Equalizer
● Voice Cancellation and Key Shifting in Kara OK mode
● AVRack® Media Player
● Configuration Panel to improve Experience of User