LET9045

Overview

The LET9045 is a common source N-channel enhancement-mode lateral field-effect RF power transistor designed for broadband commercial and industrial applications at frequencies up to 1.5 GHz. It operates in common source mode at 28 V, delivering high gain and broadband performance. Key electrical parameters include an output power of 45 W with 18.5 dB gain at 945 MHz, a continuous drain current of 9 A, and a drain-source breakdown voltage of 90 V. The device features excellent thermal stability and is housed in a BeO-free M243-3 package suitable for surface mount installation.

Feature Summary

• High gain and broadband performance optimized for common source operation
• Excellent thermal stability for reliable high-power RF applications
• BeO-free package construction compliant with environmental directives

Applications

• Base station transmitter modules requiring high linearity
• Broadband commercial RF power amplification
• Industrial RF heating and plasma generation systems

Procurement Notes

Verify the specific suffix variant (e.g., C or F) against your schematic requirements, as packaging and minor electrical tolerances may differ between sub-types. Confirm RoHS compliance status directly with the manufacturer or authorized distributor prior to ordering, as regulatory declarations can vary by production batch. Ensure thermal management solutions are compatible with the M243-3 package footprint to maintain optimal junction temperatures during high-power operation.

Selection Notes

Select this component when designing broadband RF power stages operating near 1 GHz that require high linearity and gain without excessive complexity. The 28 V supply requirement aligns with standard telecom infrastructure voltages. Consider the 90 V breakdown voltage margin for robustness against load mismatches. This LDMOS technology offers a balance of power density and thermal handling suitable for compact base station form factors where traditional vacuum tubes are impractical.

Part Context

The LET9045 belongs to STMicroelectronics' portfolio of lateral DMOS RF transistors, engineered specifically for high-frequency power amplification. It complements other devices in the series by offering a standardized pinout and thermal profile, facilitating design reuse across different frequency bands within the HF spectrum. The device represents a solid-state solution replacing older technologies in modern cellular infrastructure.

Replacement Considerations

Direct substitutes include the LET9045C and LET9045F variants, which share core electrical characteristics but may differ in package details or specific test conditions. Cross-reference pinouts and thermal pad configurations carefully before swapping to ensure mechanical compatibility on existing PCB layouts.