NCP1937A3DR2G

Overview

The NCP1937A3DR2G is a combination Power Factor Correction (PFC) and Quasi-Resonant Flyback controller designed for compact, high-efficiency Switched Mode Power Supplies. It integrates CrM PFC with maximum frequency clamp and a proprietary valley-lockout circuitry for stable quasi-resonant flyback operation. The device supports skip mode for low standby power and toggles to frequency foldback beyond the fourth valley to eliminate audible noise. Operating voltage ranges from 9V to 30V, with an operating temperature range of -40°C to 125°C.

Feature Summary

• Integrates Critical Conduction Mode (CrM) PFC and quasi-resonant current-mode flyback control in a single IC.
• Features proprietary valley-lockout circuitry ensuring stable valley switching down to the fourth valley.
• Includes frequency foldback mode beyond the fourth valley to eliminate audible noise.
• Supports skip mode operation for excellent efficiency in light load conditions.

Applications

• Compact Switched Mode Power Supply adapters
• High-efficiency power factor correction stages
• Quasi-resonant flyback converter implementations

Procurement Notes

Verify the specific suffix DR2G against the official onsemi datasheet to confirm package type and tape/reel specifications. Ensure compatibility with the required input voltage range of 9V to 30V. Confirm that the 20-SOIC package fits the PCB layout constraints. Check for RoHS compliance status if required by environmental regulations.

Selection Notes

Select this component when a single-chip solution for both PFC and secondary-side regulation is required to minimize component count. It is suitable for applications demanding near-unity power factor and low standby power consumption. Consider the thermal performance within the -40°C to 125°C range during design.

Part Context

This part belongs to the NCP1937 family of combination controllers. It is manufactured by onsemi and is intended for adapter applications requiring high efficiency and compact size. The device replaces discrete solutions by integrating both control loops into one package.

Replacement Considerations

NCP1937C61DR2G is listed as a related product in distributor catalogs.