Method and apparatus for achieving very high-output signal swing from class-D amplifier
US9806684B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 2016 |
| Grant date | Oct 31, 2017 |
| Priority date | — |
| Expiry date | Sep 10, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/04
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus and method are disclosed for providing output signal swings that are greater than the supply voltage in a class-D amplifier. The amplifier circuit boosts the voltage across the amplifier load, such as a loudspeaker, by using capacitors to “charge pump” the voltage across the load and thus increase the voltage temporarily. This is done by using two or more output bridges rather than one, and connecting the bridges through the capacitors. For signals of less than the supply voltage, only an inner bridge, similar to a full bridge of the prior art, operates. For signals above the supply voltage, an outer bridge charges capacitors, which are then used to ‘boost’ the voltage on the bridge output for the short period of the Class-D switching period. Thus, only relatively small value boosting capacitors are needed, as they do not need to supply charge for very long.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.