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 extremely low acoustic generation 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 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.