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High Definition Audio Codec with Mono Class-D Speaker Amplifier
General Description

The ALC231 is a High Definition Audio Codec that integrates a 4-channel DAC, 4-channel ADC, and a mono and filter-less Class-D Speaker Amplifier with 2Watt (rms) output power.

The 4-channel DAC and 4-channel ADC support two independent stereo sound outputs and two independent stereo inputs simultaneously; allowing multiple streaming playback and output for multimedia applications and voice communication.

The ALC231 supports stereo digital microphone channels (microphone array) with Acoustic Echo Cancellation (AEC), Beam Forming (BF), and Noise Suppression (NS) technology simultaneously, significantly improving voice quality for PC VoIP applications.

The ALC231 headphone amplifier can drive a 32Ω headphone load without external DC blocking capacitors, eliminating pop noise caused by these capacitors. In addition to the cap-free headphone output port (HP-OUT), the LINE-OUT port is also designed as a line-level output without the need for DC blocking capacitors, eliminating pop noise when connecting to external powered speakers.

The integrated mono Class-D amplifier directly drives a mini speaker with as low as 4Ω impedance. Its maximum output power is 2 Watts at 5V power supply. The built-in high-pass filter with configurable cut-off frequency can prevent speaker burn up caused by low-frequency sound. The Class-D amplifier output power can also be limited to prevent mini speaker damage.

The ALC231 has overcurrent and short circuit detection to protect the integrated Class-D amplifier and power system. The Class-D amplifier output will be automatically shut down when a connected speaker is disconnected or to prevent over-heating. As well as protection functions, the ALC231 features spread spectrum and slew rate control for the Class-D carrier frequency to reduce EMI radiation.

Support for 16/20/24-bit SPDIF output with up to 192kHz sample rate offers easy connection of PCs to consumer electronic products, or transport of digital audio output to a High Definition Media Interface (HDMI) transmitter.

The ALC231 supports host audio from Intel chipsets, and also from any other HDA compatible audio controller. With various software utilities like environment sound emulation, multiple-band and independent software equalizer, dynamic range compressor and expander, optional Dolby PCEE program, SRS TruSurround HD, SRS Premium Sound, Fortemedia SAM, Creative Host Audio, Synopsys Sonic Focus, DTS Surround Sensation | UltraPC, and DTS Connect licenses, the ALC231 offers high sound quality, providing an excellent entertainment package and game experience for PC users.

    Hardware Features
  • Meets WLP (Windows Logo Program) requirements for Windows XP, Vista, and Windows 7
  • Analog DAC outputs with 97dB Signal-to-Noise Ratio (A-weighting)
  • Analog ADC inputs with over 90dB Signal-to-Noise Ratio (A-weighting)
  • 4-channel DAC supports 16/20/24-bit PCM format for independent two stereo channel playback
  • 4-channel ADC supports 16/20/24-bit PCM format for independent two stereo channel recording
  • All DACs support 44.1k/48k/96k/192kHz sample rate
  • All ADCs support 44.1k/48k/96k/192kHz sample rate
  • SPDIF-OUT supports 16/20/24-bit format and 44.1/48/88.2/96/192kHz sample rate
  • Six stereo analog IO ports: LINE-OUT (output), MIC1 (input and output), MIC2 (input), LINE1 (input and output), LINE2 (input and output), and HP-OUT (output)
  • One mono port with Class-D Amplifier to driver mini speaker: MONO-OUT
  • One stereo digital microphone input
  • Supports external PCBEEP input and built-in digital BEEP generator
  • Built in headphone amplifiers at port LINE1 and HP-OUT
  • Headphone amplifier at port HP-OUT does not require DC blocking capacitors
  • Port LINE-OUT is stereo output without DC blocking capacitors
  • Software selectable 2.3V/3.0V/4.0V VREFOUT as bias voltage for analog microphone input
  • Programmable +12/+24/+36dB boost gain for analog microphone input
  • Programmable boost gain and volume control for digital microphone input
  • Two jack detection pins; each can detect up to 4 jacks
  • Supports 4-pole type headset combo jack (stereo headphone output and mono microphone input on a single jack)
  • Enhanced power management features for normal operation and standby mode
  • Mono Bridge-Tied Load Class-D amplifier at port-H (MONO-OUT) has 2Watt (rms) power for 4Ω load speaker
  • Short circuit and over current protection for Class-D amplifier
  • Class-D amplifier has high pass filter with selectable Cut-Off frequency to prevent low frequency signal damaging speaker
  • Class-D amplifier output with slew rate and spread spectrum control to reduce EMI radiation
  • Intel low power ECR HDA015-B compliant: supports power status control, jack detection, and wake-up event in D3 mode
  • Two GPIOs for customized applications
  • EAPD (External Amplifier Power Down) is supported
  • Supports anti-pop mode when analog power AVDD is on and digital power is off
  • PCBEEP pass through to MONO-OUT port (Class-D amplifier) in anti-pop mode
  • Built-in 5V-to-4.5V LDO to power analog circuitry
  • Power support: 3.3V digital core power; 1.5V~3.3V digital IO power for HDA link; 4.5V~5.5V analog power; 4.5V~5.5V power stage voltage
  • 48-pin QFN ‘Green’ package

    Software Features
  • Meets WLP (Windows Logo Program) requirements for Windows XP, Vista, and Windows 7
  • Supports Linux driver based on kernel 2.6.0 and later version
  • EAX 1.0 & 2.0 compatible
  • Direct Sound 3D compatible
  • I3DL2 compatible
  • HRTF 3D Positional Audio (Windows XP only)
  • Multi-band software equalizer and dynamic range control (expander, compressor, and limiter) with adjustable parameters
  • Intuitive Configuration Panel (Realtek Audio Manager) to enhance user experience
  • Enhanced Microphone Acoustic Echo Cancellation (AEC), Noise Suppression (NS), and Beam Forming (BF) technology for voice application
  • HDMI audio driver for Intel and AMD chipsets
  • Optional Dolby PCEE program, SRS TruSurround HD, SRS Premium Sound, Fortemedia SAM, Creative Host Audio, Synopsys Sonic Focus, DTS Surround Sensation | UltraPC, and DTS Connect licenses
  • Commercial desktop and notebook PCs
  • Tablet PC, netbook, and MID (Mobile Internet Device) with High Definition Audio Controller
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