Method and apparatus for extending the bandwidth of a Class D amplifier circuit
US7161428B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 26, 2005 |
| Grant date | Jan 9, 2007 |
| Priority date | — |
| Expiry date | Aug 10, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/459
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Class D amplifiers are used for their high efficiency, but they have some undesirable characteristics that limit their useable bandwidth, one of these being the residual switching frequency ripple. Embodiments of the present invention comprise methods and apparatuses for reducing the switching frequency ripple using a technique known herein as ripple steering. The zero ripple class D amplifier is used in a hybrid system comprising a linear amplifier. The hybrid Class D amplifier is modified for extended bandwidth and lowered distortion by the addition of a linear current source feeding output capacitor. The low frequency bandwidth limit on the linear current source is matched to the high frequency bandwidth limit on the Class D current source, resulting in a composite linear/switching current source with bandwidth extended to the high frequency bandwidth limit of the linear current source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.