MAX1821EUB

Overview

The MAX1821EUB is a specialized switching voltage regulator designed for WCDMA power amplifier applications. It operates as a buck converter with a fixed internal switching frequency of 1.2MHz, eliminating the need for external timing components. The device integrates a 1.55A current-mode controller and supports an input voltage range suitable for single-cell phone battery operation. It features a compact 10-pin µMAX package to minimize board space requirements.

Feature Summary

• Integrated high-frequency switching regulator optimized for RF power amplification
• Fixed 1.2MHz switching frequency reduces external component count
• Built-in current-mode control for stable operation under varying loads

Applications

• WCDMA power amplifier biasing
• Mobile phone power management systems
• RF circuit voltage regulation

Procurement Notes

Verify the specific suffix (e.g., EUB vs XEBC) against the design schematic, as package variations exist within the MAX1821 family. Confirm RoHS compliance status through official manufacturer documentation prior to integration. Ensure the selected variant matches the required thermal performance for the target enclosure.

Selection Notes

Select this component when designing for WCDMA PA applications requiring a compact, fixed-frequency solution. Compare against the MAX1820 if adjustable output voltage or different packaging options are necessary. Evaluate the 1.55A current limit against peak PA demand to ensure adequate headroom without excessive heat dissipation in the µMAX footprint.

Part Context

Part of the MAX1820/MAX1821 series of advanced power management ICs. These devices are engineered specifically for cellular handsets, offering efficient voltage conversion for RF sections. The series provides alternatives for various form factors, including UCSP and µMAX packages, catering to different size constraints in mobile designs.

Replacement Considerations

The MAX1820YEUB serves as a functional alternative within the same family, offering similar regulation capabilities but potentially differing in pinout or package dimensions. Verify compatibility before substitution.