Synchronous rectifier circuits and method for utilizing common source inductance of the synchronous FET
US7492138B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 2005 |
| Grant date | Feb 17, 2009 |
| Priority date | — |
| Expiry date | Jan 12, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of improving the operation of a synchronous rectifier circuit which includes a switching transistor and synchronous transistor, by providing an operatively effective value of inductance in the current path of the synchronous transistor; which is shared by the control terminal circuit path of the transistor and by selecting a synchronous transistor having a low resistance to a control signal provided at the control terminal, as well as improved synchronous rectifier circuits designed according to the method. When the transistors are MOSFETs, the inductance provided is preferably a purely parasitic common source inductance in the range of about 2 nH to about 3 nH. The synchronous transistor exhibits a low value of gate resistance to facilitate fast energy exchange between the common source inductance and the gate-source capacitance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.