The NCP1338 combines a true current mode modulator and a
demagnetization detector which ensures full Borderline/Critical
Conduction Mode in any load/line conditions together with minimum
drain voltage switching (Quasi−Resonant operation). The transformer
core reset detection is done internally, without using any external
signal, due to the Soxyless concept. The frequency is internally
limited to 130 kHz, preventing the controller from operating above
the 150 kHz CISPR−22 EMI starting limit.
Features
• 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
Typical Applications
• 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.)
