公开(公告)号：US10110181B2

公开(公告)日：2018-10-23

申请号：US15423093

申请日：2017-02-02

申请人： TEXAS INSTRUMENTS INCORPORATED

发明人： Søren Bang Poulsen ,  Kim Nordtorp Madsen

IPC分类号： H03F3/217 ,  H03F3/185 ,  H03F1/32

摘要： A fixed frequency class-D audio amplifier includes the L-C output filter in a high order feedback loop. An audio amplifier integrated circuit includes an output driver, an output terminal, a first input terminal, a second order filter, and a summing amplifier. The output driver is configured to drive a speaker coil through an L-C filter. The output terminal is to couple the output driver to an input side of the L-C filter. The first input terminal is to couple an output side of the L-C filter to the integrated circuit. The second order filter includes a first filter stage, and a second filter stage coupled to an output of the first filter stage. The summing amplifier includes a first input coupled to the first input terminal, and a second input coupled to an output of the second filter stage.