Method of attenuating zero crossing distortion and noise in an amplifier, an amplifier and uses of the method and the amplifier
US6373336B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 2001 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Apr 27, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/372
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
According to the invention, a method and an amplifier e.g. of the class D type, in particular connected as class BD, wherein an audio signal is pulse-with modulated in that two sets of switches are adapted to make and break signal paths transferring pulses representing the non-inverted or inverted part of the audio signal, comprise attenuating noise and zero crossing distortion which occur because of crosstalk between modulator and control circuit halves in the amplifier. Noise and zero crossing distortion are attenuated by delaying the pulses which represent the non-inverted part and the inverted part, respectively, of the audio signal relative to each other, when the audio signal is in the vicinity of the value 0, thereby achieving modulation of the audio signal which contains characteristics from pulse with modulation of both class AD and BD type. The advantage of this is that at low signal levels the amplifier obtains the linear properties of the class AD amplifiers at zero crossing and the low noise of the class BD amplifier. The pulse-with modulation type is here called class ABD.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.