BLF278/01,112

Overview

The BLF278/01,112 is a VHF push-pull power MOS transistor manufactured by Ampleon USA Inc. It is a dual common-source silicon N-channel enhancement mode vertical D-MOS device housed in an SOT262A1 balanced flange package with two ceramic caps and gold metallization. The mounting flange serves as the common source connection. Key electrical parameters include a drain-source voltage of 125 V, a total power dissipation of 500 W, and a junction temperature limit of 200 °C. In Class-B operation at 108 MHz and 50 V, it delivers 300 W output power with greater than 20 dB gain and over 60% efficiency.

Feature Summary

• Dual push-pull configuration for balanced RF amplification
• Gold metallization for enhanced reliability
• Integrated mounting flange acting as common source

Applications

• VHF broadcast transmitters
• High-power amplifier stages operating in the VHF frequency range

Procurement Notes

Verify component authenticity through authorized channels due to discontinued status. Confirm RoHS compliance and check for specific binning groups (e.g., A-Z) required for threshold voltage matching in push-pull designs. Ensure handling procedures account for beryllium oxide content in the ceramic package.

Selection Notes

Select based on required operating frequency within the VHF band and thermal management capabilities. Match gate-source threshold voltage groups to ensure symmetry between the two internal sections. Verify that the application circuit can handle the specified load mismatch ruggedness of VSWR 7:1.

Part Context

Originally developed by Philips Semiconductors, this component was transferred to Ampleon in 2015. It belongs to the legacy VHF power transistor series designed for robust performance in broadcast applications. The SOT262A1 package provides high power density and efficient heat dissipation via the flange mount.

Replacement Considerations

No direct public substitute part numbers are confirmed in the provided documentation. Designers should evaluate equivalent VHF push-pull LDMOS or MOSFET devices from current manufacturers, ensuring compatibility with the SOT262A1 footprint and thermal requirements.