EDN Magazine — 05.25.95 Class D amplifiers provide high efficiency for audio systems (figure)

FIGURE 5

Fig 5—In this feedback network, a differential lowpass filter (IC_1C and associated components) attenuates the half-bridge's output by a factor of 11. IC_1B ac couples the audio input, and an integrating error amplifier (IC_1A) sums the filtered feedback signal and the buffered audio input.