Housed in SO-8 or DIP-8 package, the NCP1200 represents a major leap toward ultra-compact Switch-Mode Power Supplies. Thanks to a novel concept, the circuit allows the implementation of a complete offline battery charger or a standby SMPS with few external components. Furthermore, an integrated output short-circuit protection lets the designer build an extremely low-cost AC/DC wall adapter associated with a simplified feedback scheme.
With an internal structure operating at a fixed 40 kHz, 60 kHz or 100 kHz, the controller drives low gate-charge switching devices like an IGBT or a MOSFET thus requiring a very small operating power. Thanks to current-mode control, the NCP1200 drastically simplifies the design of reliable and cheap offline converters with excellent audio- susceptibility and inherent pulse-by-pulse control.
When the current setpoint falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the so-called skip cycle mode and provides excellent efficiency at light loads. Because this occurs at low peak current, no acoustic noise takes place.
Finally, the IC is self-supplied from the DC rail, eliminating the need of an auxiliary winding. This feature ensures operation in presence of low output voltage or shorts.

• No Auxiliary Winding Operation
• Internal Output Short-Circuit Protection
• Extremely Low No-Load Standby Power
• Current-Mode with Skip-Cycle Capability
• Internal Leading Edge Blanking
• 250 mA Peak Current Source/Sink Capability
• Internally Fixed Frequency at 40 kHz, 60 kHz and 100 kHz
• Direct Optocoupler Connection
• Built-in Frequency Jittering for Lower EMI
• SPICE Models Available for TRANsient and AC Analysis
• Internal Temperature Shutdown
• Pb-Free Packages are Available