QUASI−RESONANT PWM CONTROLLER FOR HIGH POWER AC−DC WALL ADAPTERS
●The NCP1380 hosts a high−performance circuitry aimed to powering quasi−resonant converters. Capitalizing on a proprietary valley−lockout system, the controller shifts gears and reduces the switching frequency as the power loading becomes lighter. This results in a stable operation despite switching events always occurring in the drain−source valley. This system works down to the 4th valley and toggles to a variable frequency mode beyond, ensuring an excellent standby power performance.
●Features
●•Quasi−Resonant Peak Current−Mode Control Operation
●•Valley Switching Operation with Valley−Lockout for Noise−Immune Operation
●•Frequency Foldback at Light Load to Improve the Light Load Efficiency
●•Adjustable Over Power Protection
●•Auto−Recovery or Latched Internal Output Short−Circuit Protection
●•Fixed Internal 80 ms Timer for Short−Circuit Protection
●•Combined Overvoltage and Overtemperature Protection (A and B Versions)
●•Combined Overvoltage Protection and Brown−Out (C and D Versions)
●•+500 mA / −800 mA Peak Current Source/Sink Capability
●•Internal Temperature Shutdown
●•Direct Optocoupler Connection
●•Extended VCCRange Operation Up to 28 V
●•Extremely Low No−Load Standby Power
●•SO−8 Package
●•These Devices are Pb−Free and are RoHS Compliant
●Typical Applications
●•High Power ac−dc Converters for TVs, Set−Top Boxes etc.
●•Offline Adapters for Notebooks
