BFG505/X,235

Overview

The BFG505/X,235 is an NPN silicon planar epitaxial transistor housed in a 4-pin dual-emitter SOT143B plastic package. It features gold metallization for reliability and is designed for RF front-end applications in the GHz range. Key electrical parameters include a collector-base voltage (VCBO) of 20 V, a DC collector current (IC) limit of 18 mA, and a total power dissipation (Ptot) of 150 mW at a soldering point temperature (Ts) of 130 °C or lower. The device exhibits a transition frequency (fT) of 9 GHz at VCE = 6 V and IC = 5 mA. At 900 MHz, it provides a maximum unilateral power gain (GUM) of 20 dB and an insertion power gain (|S21|²) of 17 dB. The noise figure (F) ranges from 1.2 dB to 1.7 dB at 900 MHz with IC = 1.25 mA.

Feature Summary

• High power gain suitable for RF amplification
• Low noise figure for sensitive signal reception
• High transition frequency enabling GHz-range operation
• Gold metallization ensuring excellent long-term reliability

Applications

• Analog and digital cellular telephones
• Cordless telephones (CT1, CT2, DECT)
• Radar detectors
• Satellite TV tuners (SATV)

Procurement Notes

Verify the specific ordering suffix

Selection Notes

Select this component for designs requiring high-frequency performance up to 9 GHz with low noise characteristics. Ensure the operating conditions remain within the absolute maximum ratings, particularly the 150 mW power dissipation limit and the 18 mA DC collector current. Consider the thermal resistance of 290 K/W when designing heat dissipation strategies for the SOT143B package.

Part Context

The BFG505/X belongs to the BFG505 family of NPN wideband transistors manufactured by NXP Semiconductors. This series is engineered for high-reliability RF applications, utilizing gold metallization to enhance durability. The X variant shares core electrical specifications with the standard BFG505 but may differ in packaging or marking codes as defined in the product specification.

Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the source material. Designers should consult NXP Semiconductors directly for equivalent components or cross-reference options that match the SOT143B package and 9 GHz performance requirements.