Method and apparatus for reducing audio noise in a switching regulator
US6525514B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 2000 |
| Grant date | Feb 25, 2003 |
| Priority date | — |
| Expiry date | Oct 23, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A switching regulator utilizing on/off control that reduces audio noise at light loads by adjusting the current limit of the switching regulator. In one embodiment, a switching regulator includes a state machine that adjusts the current limit of the switching regulator based on a pattern of feedback signal values from the output of the power supply for a preceding N cycles of the drive signal. The state machine adjusts the current limit lower at light loads such that cycles are not skipped to reduce the operating frequency of the switching regulator into the audio frequency range until the flux density through the transformer is sufficiently low to reduce the generation of audio noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.