Realtek PDF datasheets for ALC221

The ALC221 is a High Definition Audio Codec that integrates 4-channel DAC, 4-channel ADC, and a mono and filter-less Class-D Speaker Amplifier with 2 Watt (rms) output power.

The 4-channel DAC and 4-channel ADC support two independent stereo sound outputs and two independent stereo inputs simultaneously, supporting multiple streaming playback and output for multimedia applications and voice communication. The codec has high performance and characteristics meets WLP (Windows Logo Program) audio requirements for Windows XP, Windows Vista and Windows 7 systems.

The ALC221 supports stereo digital microphone input with boost gain and digital volume control. With Realtek second generation of software Acoustic Echo Cancellation (AEC), Beam Forming (BF), and Noise Suppression (NS) technology, significantly improving voice input quality for VoIP application on PCs.

ALC221 has headphone amplifier can drive 32Ω headphone load without external DC blocking capacitors, eliminating pop noise caused by these capacitors. Addition to the cap-free headphone output port (HP-OUT), port LINE-OUT is also designed as a line level output without the need for DC blocking capacitors, that can keep away from pop noise whiling line level output connected to external power speaker.

The integrated mono Class-D amplifier is a filter-free design to directly drive mini speaker with as low as 4Ω impedance. Its maximum output power exceeds 2 Watt at 5V power supply. The inside high pass filter with selectable cut off frequency can prevent speaker burn up by low frequency sound. The class D amplifier output power also could be limited to avoiding damage mini speaker. ALC221 has over current and short circuit detection to protect integrated Class D amplifier and power system. Class D amplifier output will be shut down when connected speaker is broken with short and over-heating. More than protection functions, ALC221 has spread spectrum and slew rate control for Class D carrier frequency can reduce EMI radiation when Class D amplifier is in active.

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

The ALC221 supports host audio from the 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 DTS CONNECT and Surround Sensation UltraPC, SRS TruSurround HD, SRS Premium Sound and Dolby Digital Live, Dolby PCEE program and 3rd party voice processing (Noise Suppression/Acoustic Echo Cancellation/Beam Forming) technology, the ALC221 provides an excellent package for PC users.