Constant current and voltage controller in a four-pin package with dual-use pin
US7522431B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2007 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Jul 31, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0009
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A comparing circuit and a control loop are used to maintain the peak level of current flowing through an inductor of a flyback converter. An inductor switch control signal controls an inductor switch through which the inductor current flows. The inductor current increases at a ramp-up rate during a ramp time and stops increasing at the end of the ramp time. The comparing circuit generates a timing signal that indicates a target time at which the inductor current would reach a predetermined current limit if the inductor current continued to increase at the ramp-up rate. The control loop then receives the timing signal and compares the target time to the end of the ramp time. The pulse width of the inductor switch control signal is increased when the target time occurs after the end of the ramp time. Adjusting the pulse width controls the peak of the inductor current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.