A NEW TYRE DIGITAL AUDIO POWER AMPLIFIER

摘要

A novel digital audio frequency power amplifier belongs to a digital audio frequency power amplifier. An analogue output of the work of a last-stage power tube of the power amplifier is got via a lowpass filter in the on-off state, and the output is A/D-converted to get a digital signal, which is the fed back to an arithmetic logic unit; the arithmetic logic unit controls the conducting and stopping of the last-stage power tube based on the deviation of the analogue output, and controls the deviation within an acceptable scope. Moreover, a digital, negative feedback, celestial-gate and changeable power source is made based on the sample principle to supply power to the last-stage power tube. When the power amplifier outputs the high power level, the changeable power source outputs the high voltage. When the power amplifier outputs the low power level, the changeable power source outputs the low voltage. Thus, the digital function of high efficiency and low fidelity is achieved by reducing the on-off frequency of the last-stage power tube.