BCX70J

Overview

The BCX70J is an NPN epitaxial silicon transistor manufactured by ON Semiconductor, formerly Fairchild. It operates with a collector-emitter voltage of 45 V and a maximum DC collector current of 200 mA. The device features a collector power dissipation rating of 350 mW at 25°C ambient temperature. Electrical characteristics include a minimum DC current gain (hFE) of 40 at IC=10µA and up to 460 at IC=50mA. The component utilizes a SOT-23 surface-mount package.

Feature Summary

• Epitaxial silicon construction for reliable general-purpose switching
• Low saturation voltage for efficient signal handling
• High current gain across multiple operating points

Applications

• General purpose amplification
• Switching applications
• Driver circuits

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official database, as legacy Fairchild part numbers may have been updated during integration. Confirm that the requested variant matches the required electrical specifications and packaging format before finalizing procurement orders.

Selection Notes

Select this component for low-voltage, low-current applications requiring standard NPN switching or amplification. Ensure the design accounts for the 350 mW power dissipation limit and verify that the SOT-23 package dimensions fit the target PCB layout constraints.

Part Context

This component belongs to the BCX series of small-signal bipolar junction transistors. Originally produced by Fairchild Semiconductor, it is now managed under the ON Semiconductor portfolio following corporate integration. The device serves as a standard discrete semiconductor solution for consumer and industrial electronics.

Replacement Considerations

Consult the official datasheet for complementary PNP types within the same family. Verify pinout compatibility and electrical ratings when substituting with equivalent parts from other manufacturers.