Feedforward active filter for output ripple cancellation in switching power converters
US5668464A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 1996 |
| Grant date | Sep 16, 1997 |
| Priority date | — |
| Expiry date | Oct 25, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/565
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An active filter provides ripple cancellation in a DC-DC converter. The feedforward filter applies to any converter with an output filter inductor. The filter is inherently stable, performs in both continuous and discontinuous conduction modes, and applies to resonant converters. A suitable linear amplifier, combined with a current transformer, results in a low loss implementation. An adaptive tuning scheme compensates for inductance variation and drift. The filter is usable with buck, push-pull, and boost converter topologies. The result is output ripple below 10 mV.sub.RMS. The filter is effective on converters with outputs as low as 2 V and currents beyond 30 A.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.