BC847A

Overview

The Diotec Semiconductor BC847A is a small-signal NPN bipolar junction transistor housed in an SOT-23 surface-mount package. It features a collector-emitter voltage (VCEO) of 45 V and a collector-base voltage (VCBO) of 50 V, with a maximum DC collector current of 100 mA. The device offers three distinct DC current gain groups: Group A (hFE 110–220), Group B (hFE 180–450), and Group C (hFE 290–800). Power dissipation is rated at 250 mW for industrial grades and 200 mW for commercial grades. The transition frequency (fT) reaches 300 MHz, and the operating temperature range spans from -55°C to +150°C.

Feature Summary

• Three selectable DC current gain groups (A, B, and C) for precise amplification control
• Compliant with automotive reliability standards via specific suffixes (-Q/-AQ)
• Utilizes gold bond wires for standard grades and copper bond wires for commercial grades

Applications

• Signal processing circuits
• General-purpose switching applications
• Amplification stages

Procurement Notes

Verify the specific ordering suffix to confirm the required performance grade. The absence of a suffix indicates industrial grade, while the -C suffix denotes commercial grade with lower power dissipation. Suffixes -Q and -AQ indicate compliance or qualification with AEC-Q101 automotive standards. Confirm RoHS compliance status and REACH registration requirements before finalizing procurement specifications.

Selection Notes

Select the appropriate current gain group based on circuit stability requirements. Group A provides the lowest gain variation, while Group C offers higher amplification. Ensure the thermal resistance and power dissipation limits align with the PCB layout, as ratings differ between commercial and industrial grades. Verify that the 45 V collector-emitter voltage meets the system's maximum operating conditions.

Part Context

The BC847A belongs to the BC846 through BC850 series of SMD general-purpose NPN transistors. This family shares common mechanical dimensions and packaging formats but varies in voltage ratings and gain characteristics. The BC847 variant specifically targets applications requiring moderate voltage handling compared to the higher-voltage BC846 or lower-voltage BC848/BC849 models.

Replacement Considerations

Direct functional substitutes within the same manufacturer family include BC847B and BC847C, which offer different gain ranges. Complementary PNP transistors such as BC857A are available for push-pull configurations. Cross-manufacturer replacements must match the 45 V VCEO rating and SOT-23 footprint.