BLF242

Overview

The BLF242 is a silicon N-channel enhancement mode vertical D-MOS transistor designed for professional transmitter applications in the HF/VHF frequency range. It operates with a drain-source voltage of up to 65 V and delivers an output power exceeding 5 W at 175 MHz under Class-B conditions. The device features high power gain, low noise, and excellent thermal stability. Encapsulated in a 4-lead SOT123A flange package with a ceramic cap, it includes gold metallization for reliability. Key electrical parameters include a breakdown voltage of 65 V, a threshold voltage range of 2.0–4.5 V, and a maximum total power dissipation of 16 W.

Feature Summary

• High power gain and low noise characteristics suitable for professional transmitter applications
• Robust ruggedness capable of withstanding full load mismatch conditions
• Gold metallization ensures excellent long-term reliability
• Integrated ESD protection and easy power control capabilities

Applications

• Professional broadcast transmitter applications in the HF/VHF bands
• Industrial, scientific, and medical (ISM) equipment operating in HF/VHF ranges
• Broadband RF power amplification circuits requiring high thermal stability

Procurement Notes

Verify the specific manufacturing origin and date code when sourcing from secondary distributors like Rochester Electronics. Confirm that the component retains its original anti-static packaging integrity. Check for any Customer Product/Process Change Notifications (CPCN) issued by Ampleon or Philips regarding design updates. Ensure compliance with local hazardous substance regulations, particularly concerning beryllium oxide content.

Selection Notes

Select this component for designs requiring reliable HF/VHF power amplification with high thermal stability. Consider the SOT123A flange package for effective heat sinking requirements. Evaluate the gate-source threshold voltage group (A-Z) to match biasing circuit precision needs. Ensure the application environment supports the specified junction temperature limits and handles the associated thermal resistance values effectively.

Part Context

Originally manufactured by Philips Semiconductors, the BLF242 production was transferred to Ampleon following the separation of the RF Power division in December 2015. Rochester Electronics LLC acts as a distributor for obsolete or non-current production stock of this legacy part. The datasheet reflects the original Philips specifications, noting the transition to Ampleon branding for future documentation.

Replacement Considerations

Consult official Ampleon cross-reference lists for direct replacements. Verify pinout compatibility and thermal resistance values if substituting with other LDMOS transistors in the same family. Ensure replacement parts meet the same HF/VHF performance criteria and package dimensions.