FAN5903UCX

Special Purpose Regulators Overview

The FAN5903UCX is a synchronous buck converter designed for powering RF power amplifiers in 3G, 3.5G, and 4G mobile handsets. It operates with an input voltage range of 2.7 V to 5.5 V and provides a programmable output voltage from 400 mV to 3.5 V. The device delivers up to 2.4 A of output current with a switching frequency between 3 MHz and 6 MHz. Packaged in a compact WLCSP-9 format, it supports surface-mount installation and functions within a temperature range of -40°C to +85°C.

Special Purpose Regulators Feature Summary

• Integrated synchronous rectification for high efficiency in portable applications
• Programmable output voltage via external resistor divider
• Fixed-frequency PWM operation with adjustable switching frequency
• Compact wafer-level chip scale packaging for minimal footprint

Special Purpose Regulators Applications

• Powering RF power amplifiers in 3G/3.5G cellular handsets
• Powering RF power amplifiers in 4G LTE mobile devices
• General-purpose low-voltage DC-DC conversion for portable electronics

Special Purpose Regulators Procurement Notes

Verify component authenticity through authorized onsemi channels due to discontinued status. Confirm package integrity as the WLCSP-9 form factor requires careful handling during assembly. Review the latest datasheet for any updates regarding pin compatibility or thermal characteristics before finalizing design integration.

Special Purpose Regulators Selection Notes

Select this component when designing for 3G to 4G PA supply requirements needing a small solution size. Ensure the application input voltage remains within the 2.7 V to 5.5 V range. Verify that the required output current does not exceed 2.4 A and that the desired output voltage falls between 400 mV and 3.5 V for proper regulation.

Special Purpose Regulators Part Context

This part belongs to the FAN5903 series of high-efficiency buck converters developed by Fairchild Semiconductor, now integrated into onsemi. It is specifically optimized for battery-powered mobile communication devices requiring efficient power management for RF stages.

Special Purpose Regulators Replacement Considerations

Check onsemi documentation for updated part numbers following the Fairchild integration. Verify if newer revisions maintain identical pinouts and electrical specifications for direct substitution in existing designs.