onsemi NCP1337PG

The NCP1337 implements a standard current mode architecture where the switch−off time is dictated by the peak current setpoint, whereas the core−reset detection triggers the turn−on event. This component represents the ideal candidate where low part−count is the key parameter, particularly in low−cost AC−DC adapters, consumer electronics, auxiliary supplies, etc. Due to its high−performance, high−voltage technology, the NCP1337 incorporates all the necessary features needed to build a rugged and reliable Switch−Mode Power Supply (SMPS). Quasi−Resonant Operation: Valley−switching operation is ensured whatever the operating conditions are, due to the internal soxyless circuitry. As a result, there are virtually no primary switch turn−on losses, and no secondary diode recovery losses, and EMI and video noise perturbations are reduced. The converter also stays a first−order system and accordingly eases the feedback loop design. Overcurrent Protection (OCP): When the feedback current is below minimum value, a fault is detected. If this fault is present for more than 80 ms, NCP1337 enters an auto−recovery soft burst mode. All pulses are stopped and the VCC capacitor discharges down to 5.0 V. Then, by monitoring the VCC level, the startup current source is activated ON and OFF to create a burst mode. After the current source being activated twice, the controller tries to restart, with a 4.0 ms soft−start. If the fault has gone, the SMPS resumes operation. If the fault is still there, the burst sequence starts again. The soft−start, together with a minimum frequency clamp, allow to reduce the noise generated in the transformer in short−circuit conditions. Overvoltage Protection (OVP): By continuously monitoring the...

• Free−Running Borderline/Critical Mode Quasi−Resonant Operation
• Current−Mode
• Soft−Skip Mode with Minimum Switching Frequency for Standby
• Auto−Recovery Short−Circuit Protection Independent of Auxiliary Voltage
• Overvoltage Protection
• Brown−Out Protection
• Two Externally Triggerable Fault Comparators (one for a disable function, and the other for a permanent latch)
• Internal 4.0 ms Soft−Start
• 500 mA Peak Current Drive Sink Capability
• 130 kHz Max Frequency
• Internal Leading Edge Blanking
• Internal Temperature Shutdown
• Direct Optocoupler Connection
• Dynamic Self−Supply with Levels of 12 V (On) and 10 V (Off)
• SPICE Models Available for TRANsient and AC Analysis
• These are Pb−Free Devices

• AC−DC Adapters for Notebooks, etc.
• Offline Battery Chargers
• Consumer Electronics (DVD Players, Set−Top Boxes, TVs, etc.)
• Auxiliary Power Supplies (USB, Appliances, TVs, etc.)