BC549BTA

Single Bipolar Transistors Overview

The BC549BTA is an NPN epitaxial silicon transistor from the onsemi BC546-BC550 series, housed in a TO-92-3 kinked lead package. It supports a maximum collector current of 100 mA and a collector-emitter voltage (VCEO) of 30 V. The device features a power dissipation rating of 500 mW and a transition frequency (fT) of 300 MHz. Key electrical limits include a collector-base voltage (VCBO) of 30 V, an emitter-base voltage (VEBO) of 5 V, and a maximum operating temperature of +150 °C.

Single Bipolar Transistors Feature Summary

• Low noise performance suitable for sensitive signal amplification
• Complementary pairing available with BC559 series PNP transistors
• Lead-free construction compliant with environmental directives

Single Bipolar Transistors Applications

• General-purpose small-signal amplification
• Switching applications in low-power circuits
• Audio pre-amplifier stages requiring low noise characteristics

Single Bipolar Transistors Procurement Notes

Verify the specific gain bin suffix (e.g., B, C) against design requirements, as hFE ranges vary significantly between subtypes within the BC549 family. Confirm the TO-92-3 kinked lead configuration matches PCB footprint constraints. Ensure RoHS compliance documentation aligns with target market regulations. Cross-reference datasheet revisions to confirm pinout consistency across manufacturing batches.

Single Bipolar Transistors Selection Notes

Select this component when a standard NPN switching or amplifying transistor with moderate voltage ratings is required. The 30 V VCEO limit defines its suitability for low-voltage logic interfacing. Consider the 300 MHz fT for high-speed digital applications where faster rise times are necessary compared to lower-frequency alternatives. Evaluate thermal management needs based on the 500 mW dissipation limit in enclosed environments.

Single Bipolar Transistors Part Context

This part belongs to the widely used BC546 through BC550 series of general-purpose NPN and PNP transistors. These devices are industry-standard replacements for older 2N3904 equivalents but offer optimized noise and gain characteristics. The BC549 variant specifically targets applications benefiting from improved linearity and lower noise figures compared to the BC547 or BC548 variants.

Single Bipolar Transistors Replacement Considerations

Direct substitutes include BC549B from other manufacturers such as Fairchild or Diotec, provided the hFE binning matches. Generic equivalents like 2N3904 may be used if voltage margins allow, though noise performance will differ.