MRF581G

Overview

The MRF581G is an NPN silicon RF transistor designed for high-current, low-power amplifier applications operating up to 1.0 GHz. It features a macroX package and utilizes fine line geometry with arsenic emitters and gold top metallization. Key electrical parameters include a maximum collector-emitter voltage of 15 V, a maximum collector current of 0.2 A, and a minimum DC current gain (hFE) of 30. The device exhibits a typical noise figure of 2.5 dB at 500 MHz and offers a gain of 15.5 dB at the same frequency under optimum noise conditions. It operates within a temperature range of -65°C to +175°C.

Feature Summary

• Designed for high current, low power, and low noise amplification up to 1.0 GHz
• Utilizes state-of-the-art technology including fine line geometry and arsenic emitters
• Features gold top metallization and nichrome thin-film ballasting resistors

Applications

• High current low power amplifiers
• Ultra high frequency band circuits
• Low noise amplifier stages

Procurement Notes

Verify component authenticity through authorized Microsemi or Microchip distributors. Confirm RoHS compliance status as historical data may vary. Ensure proper ESD handling during storage and assembly. Validate datasheet revisions against specific manufacturing lot requirements before integration into final designs.

Selection Notes

Select this component for UHF applications requiring low noise figures around 2.5 dB at 500 MHz. Consider the macroX package for cost-effective implementation. Verify thermal management capabilities given the 175°C maximum junction temperature rating. Ensure biasing circuits support the 0.2 A collector current limit for stable operation.

Part Context

The MRF581 series belongs to Microsemi's family of RF and microwave discrete low power transistors. These devices are engineered using advanced semiconductor processes to deliver high gain and dynamic range in compact packages. The series supports various amplifier configurations in communication systems requiring reliable performance at ultra-high frequencies.

Replacement Considerations

Consult official cross-reference lists for verified substitutes such as MRF5812 or MRF5943. Verify pinout compatibility and electrical parameter alignment before substitution. Generic equivalents may not match the specific noise or gain characteristics required for critical RF stages.