ML4800CSX

Overview

The ML4800CSX is a Power Factor Correction (PFC) controller with an integrated PWM combo, manufactured by Fairchild Semiconductor. It operates in voltage-mode control using pulse width modulation techniques and supports average current mode operation. The device is housed in a 16-pin SOIC package compliant with JEDEC MS-012 standards. Electrical specifications include a maximum input voltage of 16.5 V and a minimum operating voltage of 10.8 V, with a nominal supply of 15 V. The component is lead-free and RoHS compliant.

Feature Summary

• Integrates PFC and PWM control functions within a single controller unit
• Supports both voltage-mode and average current mode operations
• Includes a post regulator for power factor correction applications

Applications

• Power supplies utilizing boost PFC stages combined with PWM regulation
• AC-DC conversion systems requiring high power factor correction
• General-purpose power management circuits

Procurement Notes

Verify the specific suffix CSX to confirm the SOIC-16 narrow body package variant. Ensure compatibility with existing board layouts designed for the 16LD SOP footprint. Confirm that the voltage-mode control architecture aligns with the system design requirements, as this model lacks certain features found in later revisions like FAN4800A.

Selection Notes

Select this component for designs requiring a dedicated PFC and PWM combo controller in a surface-mount package. Consider the 10.8 V to 16.5 V input range for bias supply design. Note that this older generation part does not include UVLO or soft-start features present in successor models, which may impact startup behavior and protection strategies.

Part Context

The ML4800 series represents an earlier generation of PFC controllers from Fairchild Semiconductor. The ML4800CSX specifically denotes the SOIC package version. This family was widely used before being succeeded by enhanced versions such as the FAN4800A/C, which introduced lower quiescent current and additional protection features like under-voltage lockout and soft-start capabilities.

Replacement Considerations

The FAN4800A is a documented successor. Replacement requires adjusting the RAC resistor to 6MΩ–8MΩ, setting RT/CT for 64 kHz operation, and modifying the VRMS calibration for universal input ranges. Soft-start capacitor values must also be reduced due to changed current specifications.