Pulse frequency modulated voltage regulator capable of prolonging a minimum off-time
US6972548B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 2003 |
| Grant date | Dec 6, 2005 |
| Priority date | — |
| Expiry date | Jun 18, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0025
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a pulse frequency modulated (PFM) voltage regulator, a PFM switching controller is provided to generate a PFM switching signal for converting a DC voltage source to an output voltage. A minimum OFF-time controller provides the PFM switching signal with a minimum OFF-time. In response to the output voltage, a feedback circuit generates a feedback signal. When the output voltage is lower than a predetermined target voltage, an OFF-time prolonging circuit prolongs the minimum OFF-time in response to the feedback signal. In other words, a time of delivering energy to a capacitor from an inductor may be prolonged by the OFF-time prolonging circuit. Therefore, a ripple of the output voltage is effectively reduced when the PFM voltage regulator is operated in a heavy loading condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.