The NCP1336 hosts a high−performance circuitry aimed to

powering quasi−resonant converters. Capitalizing on a novel

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.

The controller takes benefit of a high−voltage start−up current

source to provide a quick and lossless power−on sequence. To improve

the safety in overload situations, the controller includes an Over Power

Protection circuit which clamps the delivered power at high−line.

Safety−wise, an adjustable timer relies on the feedback voltage to

detect a fault. On version B, this fault triggers a triple−hiccup on the

VCC pin which naturally reduces the average input power drawn by

the converter. On version A, when a fault is detected, the controller is

latched−off.

Particularly well suited for adapter applications, the controller

features two latch inputs: one dedicated to Over Temperature

protection (OTP) which offers an easy means to connect a pull−down

temperature sensor like an NTC, and a second one more classical that

can be used to perform an accurate Over Voltage Protection.

Finally, a brownout pin which stops the circuit operation in presence

of a low mains condition is included.

Features

• Quasi−Resonant Peak Current−Mode Control Operation

• Valley Switching Operation with Valley−Lockout for Noise−Immune Operation

• Internal 5 ms Soft−Start

• Loss−Free Adjustable Over Power Protection

• Auto−Recovery or Latched Internal Output Short− Circuit Protection

• Adjustable Timer for Improved Short−Circuit Protection

• Overvoltage and Overtemperature Protection Inputs

• Brownout Input

• −500 mA/+800 mA Peak Current Source/Sink Capability

• Internal Temperature Shutdown

• Direct Optocoupler Connection

• 3 s Blanking Delay to Ignore Leakage Ringing at Turn−Off

• Extremely Low No−Load and Standby Power

• SO14 Package

• These are Pb−Free Devices

• This Device uses Halogen−Free Molding Compound

Typical Applications

• High Power ac−dc Converters for TVs, Set−Top Boxes etc

• Offline Adapters for Notebooks