SD2900

Overview

The SD2900 is a gold metallized N-channel MOS field-effect RF power transistor designed for large signal applications up to 500 MHz. It operates at 28 V DC and delivers 5 W output power with a minimum gain of 13.5 dB at 400 MHz. The device supports Class A or AB operation, featuring excellent thermal stability and low junction-to-case thermal resistance of 8.0 °C/W. Key electrical parameters include a drain-source breakdown voltage of 65 V, maximum power dissipation of 21.9 W, and a typical efficiency of 50% under specified test conditions.

Feature Summary

• Gold metallization for enhanced reliability
• Common source configuration
• Excellent thermal stability

Applications

• HF/VHF/UHF RF power amplification
• Large signal applications up to 500 MHz
• Class A or AB operation circuits

Procurement Notes

Verify component status as the datasheet explicitly identifies this part as obsolete. Confirm availability through secondary market channels or authorized distributors holding legacy stock. Ensure compatibility with existing designs before procurement, as replacement components may require circuit adjustments due to parameter variations in newer generations.

Selection Notes

Select this component for applications requiring 5 W output at 400 MHz with 28 V supply. Consider thermal management requirements given the 8.0 °C/W junction-to-case resistance. Verify impedance matching networks against the provided input and load impedance data at 400 MHz. Ensure gate-source voltage limits are respected during biasing to prevent damage.

Part Context

This N-channel MOSFET belongs to STMicroelectronics' RF power transistor series, specifically targeting HF, VHF, and UHF bands. It is engineered for robust performance in large-signal environments, utilizing gold metallization to improve contact reliability and thermal characteristics compared to standard aluminum-metallized alternatives.

Replacement Considerations

No direct public substitute is confirmed in the provided documentation. As an obsolete product, designers should evaluate newer ST RF MOSFETs or third-party equivalents with similar 5 W output, 28 V operation, and 400 MHz gain specifications, ensuring pinout and thermal package compatibility.