Circuit and method for suppressing audio noise in DC-DC converters
US10615694B2 · kind B2 · utility
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17References
27Claims
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Key dates
| Filing date | Sep 7, 2018 |
| Grant date | Apr 7, 2020 |
| Priority date | — |
| Expiry date | Sep 9, 2038 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A solution is provided for suppressing audio noise in a DC-DC switching converter. A means for limiting the minimum switching frequency of a pulse-frequency modulation (PFM) control is described. A first order gm amplifier dissipates the excess energy added to the inductor, when magnetizing at faster rate than the native PFM. A higher resistance, low-side scaled switch helps reduce wasted energy losses. The low-side scaled switch reduces the rise in the inductor current during magnetization, and hence keeps efficiency up at low loads, when the PFM minimum switching frequency is active.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.