Multiple output flyback DC-to-DC converter with synchronous rectification and constant on-time current mode control
US5663874A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 1995 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Sep 19, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B70/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A multiple output flyback DC-to-DC converter with synchronous rectification and constant on-time current-mode control. A controller includes a constant on-time, minimum off-time oscillator that is coupled to control a gate of a first transistor which controls a current through a primary winding of a transformer having three secondary coupled inductors. Each of the three secondaries is coupled to a capacitor which is charged by each secondary current to an output voltage level which depends, in part, upon a ratio of windings. A transistor is coupled between each secondary winding and a resistive network. The gates of these transistors are coupled to be controlled by the controller for synchronous rectification. The resistive network monitors the secondary currents by generating a voltage signal that is representative of a weighted sum of the inductor currents. A difference between an output voltage level and a reference voltage level is added to the voltage signal generated by the resistive network for controlling the oscillator. When the voltage signal generated by the resistive network reaches a first predetermined level, the off-time of the oscillator is terminated and a new on-t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.