NCP1937C4DR2G

Overview

The NCP1937C4DR2G is a combination integrated circuit designed for Power Factor Correction (PFC) and Quasi-Resonant Flyback applications. It integrates PFC and quasi-resonant flyback controllers to implement compact, high-efficiency Switched Mode Power Supplies for adapters. The PFC stage operates in Critical Conduction Mode (CrM) with near-unity power factor and includes a maximum frequency clamp. The flyback stage utilizes proprietary valley-lockout circuitry for stable valley switching down to the fourth valley, toggling to frequency foldback mode beyond this point to eliminate audible noise.

Feature Summary

• Integrates critical conduction mode PFC and quasi-resonant flyback control in a single IC
• Proprietary valley-lockout circuitry ensures stable valley switching performance
• Frequency foldback mode activation eliminates audible noise during operation
• Skip mode operation capability for enhanced efficiency at light loads

Applications

• Compact adapter implementations
• High-efficiency switched mode power supplies
• Power factor correction stages requiring near-unity power factor

Procurement Notes

Verify the specific suffix 'C4' against the manufacturer's official datasheet to confirm pinout and functional compatibility. Ensure the ordering part number matches the exact package and tape/reel specifications required for your assembly process. Cross-reference the RoHS status and material declaration documents provided by onsemi to meet environmental compliance requirements for your target market.

Selection Notes

Select this component when a single-chip solution for both PFC and secondary-side regulation is required to minimize board space. It is suitable for designs prioritizing high efficiency and low acoustic noise through valley switching and frequency foldback features. Consider the integration level if external component count reduction is a primary design constraint for adapter applications.

Part Context

This device belongs to the NCP1937 family of combination controllers from onsemi. These ICs are engineered specifically for AC-DC conversion systems where size and efficiency are critical. The family typically offers variations in packaging and specific feature sets while maintaining the core dual-controller architecture for PFC and flyback topologies.

Replacement Considerations

Consult the official onsemi documentation for direct pin-to-pin compatible alternatives within the NCP1937 series. Verify that any substitute maintains the same CrM PFC and quasi-resonant flyback functionality. Ensure thermal and electrical characteristics match the original design requirements before implementation.