Digital audio converter and Amplifier Controller (2-ch BTL / 1-ch PBTL)

The AX5688 is a 2-channel BTL audio amplifier controller IC with digital inputs and CMOS level PWM outputs. It enables high order digital control loops, with feedback after Class-D output filters.


  • 2x BTL/PBTL
  • 1x PBTL

General Features

  • 2-channel digital Class-D amplifier controller with digital inputs
  • 4 differential low-latency ADCs with a 115 dB dynamic range
  • 8 digital filter slices
  • 4 CMOS level PWM outputs
  • Feedback loop possible after the output filter, across the loudspeaker nodes
  • Configurable interconnections between slices and ADCs for versatility and MIMO control
  • Volume control and soft mute
  • Dynamic loop control with programmable ramping enabling pop-free mode transitions

Serial audio input / output:

  • I2S / TDM Serial Audio Interface with 16 downstream and 8 upstream channels
  • Input sample rate: 32 – 768 kHz
  • 16 to 32-bit supported audio formats

Control Interface

  • SPI
  • Fast mode I2C control interface with selectable address for multi-chip system


  • Streaming audio amplifier solutions
  • TV Sound-bars, audio entertainment solutions
  • Active loudspeakers
  • High performance (buffered) DAC solutions
  • High-resolution low-latency ADC solutions

Schematic Representation

Reference Designs


More information



The request for better audio quality of home audio products is there. New home audio products are often connected to the internet. The audio path is dominantly digital, so it makes sense to stay in the digital domain towards the loudspeakers. This is exactly what Axign offers, a digital amplifier solution with balanced feedback from the loudspeaker.

More info