4.6.7 Interfacing with CLASS-D Audio Output

The Audio Class D Amplifier (CLASSD) is a digital input, pulse width modulated (PWM) output mono Class D amplifier. It features a high-quality interpolation filter embedding a digitally controlled gain, an equalizer and a de-emphasis filter.

On its input side, the CLASSD is compatible with most common audio data rates. On the output side, its PWM output can drive either:

  • high-impedance single-ended or differential output loads (Audio DAC application) or,
  • external MOSFETs through an integrated nonoverlapping circuit (Class D power amplifier application).
Figure 4-31. CLASS-D Interface Example Schematic