BFR540,235

Overview

The BFR540 is an NPN silicon planar epitaxial transistor housed in a SOT23 plastic package. It operates with a collector-base voltage of 20 V and supports a DC collector current up to 120 mA, dissipating 500 mW at temperatures below 70 °C. The device features a transition frequency of 9 GHz and a maximum unilateral power gain of 14 dB at 900 MHz. Noise figures range from 1.3 dB to 2.4 dB depending on bias conditions. Gold metallization ensures high reliability for wideband RF applications.

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 for enhanced reliability

Applications

• RF front end wideband applications in the GHz range
• Analog and digital cellular telephones
• Cordless telephones (CT1, CT2, DECT)
• Radar detectors
• Satellite TV tuners (SATV)

Procurement Notes

Verify the component against the official NXP datasheet Rev. 6 specifications before integration. Confirm that the physical marking code matches the '33' identifier followed by a country-specific suffix indicating manufacturing origin. Ensure the supplier provides traceability documentation consistent with the SOT23 package outline and lead configuration defined in the product data sheet.

Selection Notes

Select this transistor for designs requiring high-frequency performance up to 9 GHz with low noise characteristics. Evaluate the thermal resistance from junction to soldering point, which is 260 K/W, to ensure adequate heat dissipation within the 500 mW total power dissipation limit. Verify that the operating collector current remains within the 120 mA DC rating to maintain stability and prevent exceeding absolute maximum ratings during peak signal conditions.

Part Context

This component belongs to the category of NPN silicon planar epitaxial transistors designed for surface-mount technology. It is specifically engineered for radio frequency and microwave circuits where small form factors are required. The SOT23 package allows for automated assembly in compact electronic devices, supporting the miniaturization trends in modern telecommunications hardware.

Replacement Considerations

Consult the official NXP database for verified substitute part numbers. Do not assume functional equivalence with other NPN transistors without cross-referencing specific electrical parameters such as transition frequency and noise figure.

FAQ

What is the maximum transition frequency of the BFR540?

The maximum transition frequency is 9 GHz when measured at a collector current of 40 mA and a collector-emitter voltage of 8 V.

How is the BFR540 marked on the package?

The marking code consists of '33' followed by a single character indicating the manufacturing location: 'p' for Hong Kong, 't' for Malaysia, or 'W' for China.

What is the thermal resistance from junction to soldering point?

The typical thermal resistance from junction to soldering point is 260 K/W.