Patent ID: 9214907
Filing Date: 2015-12-15
Classification: H03F

Abstract:
1. A power amplifying circuit, comprising: a signal input terminal, a common-mode voltage input terminal, a power tube control unit connected with said signal input terminal and said common-mode voltage input terminal, a feedback loop connected with said signal input terminal and said power tube control unit, a driving unit connected with said power tube control unit, a first switching element connected with said power tube control unit, a second switching element connected with said power tube control unit, a low-pass filter connected with said first switching element, said second switching element, and said feedback loop, a speaker connected with said low-pass filter, a source voltage terminal connected with said power tube control unit and said first switching element, and a ground terminal connected with said power tube control unit, said second switching element, and said speaker, wherein said power tube control unit comprises: an operational amplifier, a first switch connected with said operational amplifier, a second switch connected with said operational amplifier, a third switch connected with said operational amplifier, a fourth switch connected with said third switch, a fifth switch connected with said operational amplifier, a sixth switch connected with said fifth switch, a seventh switch connected with said first switch, a eighth switch connected with said second switch, a ninth switch connected with said sixth switch, a third switching element connected with said third switch and said fourth switch, a fourth switching element connected with said fifth switch and said sixth switch, and a comparator connected with said third switching element and said fourth switching element.