Switching power supply device having a constant voltage characteristic and semiconductor device
US8451635B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 2010 |
| Grant date | May 28, 2013 |
| Priority date | — |
| Expiry date | Sep 9, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33523
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The switching power supply device includes: an input unit which receives an input voltage; a transformer which includes a primary winding and a secondary winding; an output unit which provides an output voltage; a switching element; and a control circuit. The control circuit includes: a T2on measuring unit which measures a secondary-side conduction time period; a frequency control circuit which provides a second signal used for changing an on-frequency of the switching element in order to narrow a difference between the measured secondary-side conduction time period and a reference value; a primary current detecting circuit which detects a primary current; a current comparing circuit which provides a third signal used for turning the switching element off when the detected primary current becomes equal to a threshold value; and an oscillation control circuit which controls on-off switching of the switching element according to the second signal and the third signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.