Class D amplifiers have always offered better efficiency than Class AB amplifiers for low-power applications. This inherent advantage, however, rarely outweighed the traditional disadvantages of Class D, which were higher cost, reduced audio performance, and the need for output filtering. Recent advances in Class D technology, however, have brought Class D costs and audio performance up to equal Class AB. This application note discusses some of these advances, including novel Class D output modulation schemes that ease the EMI burden in many applications.