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3W Stereo/6W Mono Class-D Audio Amplifier with I2C/PWM/Fixed Gain Volume Control
General Description

The ALC122 is a Stereo BTL or Mono PBTL Class-D audio amplifier that can drive speakers at a typical 4 in BTL mode or 2 in PBTL mode. Its maximum output power is up to Stereo BTL 3W at 5V power supply or Mono PBTL 6W at 5V power supplied when PBTL=H.

The ALC122 provides three volume control mechanisms; 64 steps I2C Volume Control, 64 steps PWM Duty Volume Control, and 4-Steps Fixed gain Volume Control.

PWM Duty Volume Control is patented by Realtek and useful for volume control in LCD monitor systems. With Realtek proprietary Class-D amplifier technology, the ALC122 offers good audio quality, high power-efficiency, requires fewer external components, and supports analog input.

The ALC122 can output power directly to the speaker with less power dissipation inside the silicon. This high efficiency with less run-time power consumption can greatly extend the battery life of portable consumer electronic devices and notebook PCs.

  • Stereo single-ended analog inputs
  • Output Power
    • Stereo BTL Po = 3W/CH at 4 load and 5V power with 10% THD+N ratio
    • Stereo BTL Po = 3W/CH at 4 load and 5V power with 10% THD+N ratio
  • Filter-less design for output
  • 64-steps PWM Duty Volume Control and range is from 30dB to -24dB monotonic steps
  • 64-steps I2C Volume Control with range from 30dB to -24dB monotonic steps
  • 4-steps Fixed Gain Volume Control (11dB /14dB /19dB /24dB)
  • Volume control types: I2C, PWM Input, and Fixed gain control
  • Pop noise suppression during Power Up/Down and Mute/Un-mute
  • Over-Current Protection (OCP) and short-circuit protection
  • Auto-recovery function to help sound recovery from OCP
  • Zero cross detection with soft volume function
  • External pin control for Shut Down mode
  • Speaker amplifier power supplies from 3V to 5.25V
  • 24-pin QFN4x4 Package
  • Notebook PCs
  • Portable Navigation Device/DVD Player/Games
  • All-in-One PC
  • Monitor, TV
  • Digital Photo Frame
  • USB Speaker


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