DESCRIPTION

· The NCP1937 is a combination IC integrating Power Factor Correction (PFC) and Quasi-Resonant Flyback functionalities for compact and efficient Switched Mode Power Supplies in adapter applications.

· It operates in Critical Conduction Mode (CrM) for near-unity power factor and includes a maximum frequency clamp.

· Features proprietary valley-lockout circuitry for stable valley switching and frequency foldback mode to eliminate audible noise.

· Skip mode operation enhances efficiency under light load conditions with minimal standby power consumption.

FEATURES

· Wide VCC range from 9V to 30V with built-in overvoltage protection.

· High-voltage startup circuit and active input filter capacitor discharge for reduced standby power.

· Integrated high-voltage brown-out detector and switch to disconnect PFC feedback resistor divider.

· Fault input for severe conditions, NTC compatible with latch and auto-recovery options.

· 0.5A / 0.8A source/sink gate drivers and internal temperature shutdown.

· Power savings mode reduces supply current to 70µA, suitable for very low input power applications.

APPLICATIONS

· Ideal for adapter applications requiring compact and highly efficient power supplies.

· Suitable for systems needing robust PFC and flyback stages with minimal external components.

· Effective in applications where low standby power and high efficiency under light load are crucial.