Control circuit for switching power supply
US8624828B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2011 |
| Grant date | Jan 7, 2014 |
| Priority date | — |
| Expiry date | Oct 21, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control IC controls a switching power supply configured to supply a driving voltage Vout to one terminal of an LED string to be intermittently driven. In the on period of the LED string, a pulse modulator generates a pulse signal having a duty ratio adjusted such that a detection voltage VLED that corresponds to the output voltage Vout of the switching power supply matches a predetermined reference voltage Vref. A driver drives a switching transistor included in the switching power supply according to the pulse signal. After transition from the on period to the off period, the pulse modulator reduces the duty ratio of the pulse signal over time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.