FAN4801FNY

Overview

The FAN4801FNY is a discontinued Power Factor Correction and PWM controller combination designed for power supplies utilizing boost PFC stages. It integrates CCM PFC and PWM control functions within a single 16-pin DIP package. The device supports voltage-mode or current-mode PWM operation with an accurate maximum duty cycle limit of 49.9 percent to extend run time. It features low operating current, under-voltage protection, and PFC soft-start capabilities, requiring minimal external components for versatile protection and compensation.

Feature Summary

• Integrates continuous conduction mode (CCM) PFC and PWM control functions into a single highly integrated chip
• Supports flexible PWM operation in either voltage-mode or current-mode configurations
• Includes built-in under-voltage protection and dedicated PFC soft-start functionality
• Features an accurate maximum PWM duty cycle limit to ensure extended operational run time

Applications

• Power supplies incorporating boost PFC topology combined with PWM regulation
• Universal input AC-DC conversion systems requiring high power factor correction
• Applications necessitating minimal external component count for protection and compensation

Procurement Notes

Verify the obsolete status of this component before integration, as it is marked as not recommended for new designs. Confirm that the specific suffix corresponds to the 16-pin DIP package variant. Ensure that existing inventory sources are authorized distributors to avoid counterfeit parts. Review replacement options such as the FAN4800A/C series if new production is required, noting necessary circuit adjustments for compatibility.

Selection Notes

Select this component for legacy system maintenance where the original design utilized the FAN4800 or ML4800 families. Evaluate the need for updated protection features like under-voltage lockout and soft-start which were absent in predecessor models. Consider the transition to surface-mount packages if board space is constrained, though this specific part number denotes through-hole packaging. Assess the impact of reduced operating current on overall system efficiency compared to older generations.

Part Context

This part belongs to the Fairchild Semiconductor FAN4800 family of power factor controllers. It serves as an evolution of the earlier ML4800 and standard FAN4800 devices, offering enhanced feature sets including improved protection mechanisms and lower quiescent current. The family is specifically engineered for applications demanding efficient power factor correction alongside stable PWM regulation in a compact form factor.

Replacement Considerations

Public confirmed substitute part numbers include the FAN4800ANY, FAN4800AMY, FAN4802NY, and FAN4801MY. When replacing, adjust the RAC resistor value to between 6MΩ and 8MΩ and modify RT/CT pins to achieve a 64kHz switching frequency. Verify VRMS settings at 85VAC input and ensure average VEA is approximately 4.5V under full load conditions.