onsemi (Ansemi)

SO-14

taping

2500

The NCP1336 contains a high performance circuit designed to power quasi-resonant converters. The controller is based on a proprietary valley lockout system that switches and reduces switching frequency when the power load becomes lighter. This will result in stable operation even under switching events that always occur in drain-source valleys. The system can operate down to the 4th valley and then switch to variable frequency mode, ensuring excellent standby power performance. The controller takes advantage of a high voltage start-up current source to provide a fast lossless power-up sequence. For added safety during overload conditions, the controller includes overpower protection circuitry that clamps the power supplied at the high line. An adjustable timer with safety features relies on a feedback voltage to detect faults. On revision B, this fault will trigger a three-pause on the VCC pin, which naturally reduces the average input power received by the converter. On version A, the controller latches off when a fault is detected. The controller has two latching inputs, especially for adapter applications: one dedicated to over-temperature protection (OTP), providing an easy way to interface a pull-down temperature sensor such as an NTC, and the other, more traditional, for Implement accurate overvoltage protection. Finally, an undervoltage pin is included to stop circuit operation in the event of a low supply condition.