Switched mode power supply integrated circuit with start-up self-biasing
US5285369A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 1, 1992 |
| Grant date | Feb 8, 1994 |
| Priority date | — |
| Expiry date | Sep 1, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/901
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An embodiment of the present invention is a switching power supply that includes a full-wave bridge rectifier to rectify incoming AC line voltage, a transformer having a primary winding and two secondary windings and a switched mode power supply chip that includes an integrated high voltage power MOSFET with a low voltage tap in the drift region. The MOSFET controls power switching of the primary winding of the transformer and has a high voltage present during initial power-up. This high voltage is dropped across the JFET part of the MOSFET and supplies a regulator with power either temporarily or continuously to operate a pulse width modulator in the chip that controls the switching of the MOSFET.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.