One pin error amplifier and switched soft-start for an eight pin PFC-PWM combination integrated circuit converter controller
US5798635A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1997 |
| Grant date | Aug 25, 1998 |
| Priority date | — |
| Expiry date | Feb 6, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P80/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A combination PFC-PWM integrated circuit converter controller having a power factor correction stage and a pulse-width modulation stage. The power factor correction stage provides unity power factor and a regulated intermediate output voltage by sensing a current in the power factor correction circuit and by sensing the regulated intermediate output voltage in a voltage control loop. The regulated intermediate output voltage is sensed by an error amplifier that includes a current mirror. A dc supply voltage for powering the integrated circuit is generated that is representative of the regulated intermediate output voltage. The dc supply voltage is sensed for an overvoltage protection function. By sensing the intermediate regulated output voltage in the voltage control loop and by sensing the dc supply voltage for overvoltage protection, a component failure is less likely to affect both functions than if a single voltage was sensed for both functions. The pulse-width modulation stage waits a predetermined delay time after start up for the output voltage to rise before beginning the pulse-width modulation function. The delay time is determined by an amount of time taken to charge a c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.