Multi-level class-D amplifier by means of 3 physical levels
US6724249B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 2002 |
| Grant date | Apr 20, 2004 |
| Priority date | — |
| Expiry date | Dec 6, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/345
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method to generate virtual multi-level output pulses for a Class-D Amplifier, where the time-voltage-area corresponds to a multiple of digital levels is achieved. A class-D Amplifier using PDM (Pulse Density Modulation) normally converts the input signal with a Sigma Delta Modulator into high-frequency pulses of equal width and typically drives an H-Bridge, with its 3 physical output levels. The disclosed invention however adds the methods to produce pulses with a multiple of discrete values of width and provides the method to generate a pulse length select control signal for these variable-width-pulses. Using multi-level pulse widths, in contrast to just a single pulse width, allows the reduction of the pulse-sampling rate by the same factor. Or Multi-level pulse widths allow a better quality output signal. In addition, better power efficiency is achievable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.