EMI filter and switching power supply with the same
US10069406B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 2016 |
| Grant date | Sep 4, 2018 |
| Priority date | — |
| Expiry date | Dec 5, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An EMI filter configured for an AC-DC switching power supply, and that is coupled between a DC-DC converter and a rectifier circuit that receives an AC power supply, can include: an input capacitor coupled in parallel to input terminals of the DC-DC converter; a transistor having a first terminal coupled to a first terminal of the input capacitor, and a second terminal coupled to ground; and a control circuit configured to generate a control signal that controls the transistor according to a feedback voltage that represents ripple information of an input voltage to the DC-DC converter, and at least one of a current that flows through the transistor, and a voltage at the first terminal of the transistor, where the control signal is used to regulate the voltage at the first terminal of the transistor to substantially eliminate switching frequency ripples from an input current of the DC-DC converter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.