FJX3012RTF

Overview

The FJX3012RTF is an NPN epitaxial silicon transistor with a built-in bias resistor, manufactured by onsemi. It operates with a collector-emitter voltage of 40 V and a collector current of 100 mA. The device features a DC current gain (hFE) ranging from 100 to 600 at IC=1mA. Key electrical parameters include a collector-base breakdown voltage of 40 V, a saturation voltage of 0.3 V at IC=10mA, and a transition frequency of 250 MHz. The integrated resistor value is typically 47 kΩ. Power dissipation is rated at 200 mW, housed in a compact SOT-323 package.

Feature Summary

• Integrated bias resistor simplifies circuit design for switching applications
• High DC current gain suitable for efficient signal amplification
• Compact SOT-323 surface-mount package for space-constrained designs

Applications

• Switching circuits
• Inverter logic gates
• Interface circuits
• Driver circuits

Procurement Notes

Verify the component origin carefully, as the datasheet indicates Fairchild Semiconductor as the original manufacturer. Confirm that the 'TF' suffix corresponds to the specific tape-and-reel packaging variant intended for automated assembly. Ensure the part number matches the exact specifications required for the target application before finalizing procurement orders.

Selection Notes

Select this component when a compact NPN transistor with a fixed base resistance is required. The typical 47 kΩ internal resistor eliminates external components, reducing board space. Verify that the 40 V voltage rating and 100 mA current capacity meet the load requirements. Consider the thermal performance within the SOT-323 package for high-frequency switching operations.

Part Context

This device belongs to the FJX series of pre-biased transistors designed for digital switching. It serves as a complement to the PNP counterpart, the FJX4012R. The series is engineered to replace discrete resistor-transistor combinations, offering a standardized solution for interface and driver stages in consumer electronics and industrial control systems.

Replacement Considerations

The FJX4012R is documented as the complementary PNP device within the same product family. Direct substitution requires verifying polarity compatibility and ensuring the replacement part meets the 40 V and 100 mA operational limits specified in the original design constraints.