Method and apparatus for filter-less class D audio amplifier EMI reduction
US8710922B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 11, 2012 |
| Grant date | Apr 29, 2014 |
| Priority date | — |
| Expiry date | May 15, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K7/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An audio system includes a speaker and a class D amplifier with a class-D PWM (pulse width modulation) modulator configured for generating first and second PWM signals forming a differential signal with three differential output levels with three differential output levels. The class-D amplifier also has a differential output driver configured for driving a first and a second output signals onto a first and a second output terminals in response to the first and the second PWM signals, wherein the first and the second output signals form a differential output signal having three differential output levels. An inverse common-mode signal generator is coupled to first and second output signals for providing an inverse common-mode signal. The audio system also includes one or more output terminals for providing the inverse common mode signal, and further includes a wire or a trace on a PCB (printed circuit board).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.