Fast startup control circuit for switch mode power supply
US9293981B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2013 |
| Grant date | Mar 22, 2016 |
| Priority date | — |
| Expiry date | May 27, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/33523
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.