Patent ID: 7728666
Filing Date: 2010-06-01
Classification: H03F

Abstract:
1. A close-loop class-D power amplifier, comprising: an input stage for receiving an input signals said input stage comprising a comparator and one of a triangular wave generator and a rectangular wave generator, said comparator receiving said input signal and one of a high-frequency triangular wave generated by said triangular wave generator and a high-frequency rectangular wave generated by said rectangular wave generator, and outputting a first signal; an output stage coupled to said input stage for responding to said first signal and generating a second signal; a filter coupled to an output node of said output stage for filtering said second signal to get an output signal; and a feedback circuit coupled between an output node of said output stage and an input node of said input stage, said feedback circuit shaping said second signal to get a feedback signal, and negatively feeding back said feedback signal to said input stage, so as to subtract said feedback signal from said input signal; wherein said high-frequency triangular wave is applied to a non-inverting input of said comparator, while said input signal and said feedback signal are applied to an inverting input of said comparator, said comparator comparing said high-frequency triangular wave with a signal which is gained by subtracting said feedback signal from said input signal, to get said first signal.