FJX4012RTF

Overview

The FJX4012RTF is a PNP epitaxial silicon transistor featuring a built-in bias resistor, manufactured by onsemi (formerly Fairchild Semiconductor). It operates with a collector-emitter voltage of -40 V and a collector current of -100 mA. The device includes an integrated resistor with values ranging from 32 kΩ to 62 kΩ. Key electrical characteristics include a DC current gain (hFE) between 100 and 600 at -1 mA, a saturation voltage of -0.3 V at -10 mA, and a transition frequency of 200 MHz. It is housed in a SOT-323 surface-mount package.

Feature Summary

• Integrated bias resistor for simplified circuit design
• High DC current gain suitable for switching applications
• Compact SOT-323 surface-mount package

Applications

• Switching circuits
• Inverter circuits
• Interface circuits
• Driver circuits

Procurement Notes

Verify the manufacturer origin carefully, as the component was originally produced by Fairchild Semiconductor before its acquisition by onsemi. Confirm that the specific suffix 'TF' corresponds to the tape-and-reel packaging format indicated in standard distribution channels. Ensure the part status is checked against current production schedules to avoid obsolete stock issues.

Selection Notes

Select this component when a compact PNP transistor with an integrated base resistor is required for low-current switching tasks. The built-in resistor eliminates external components, reducing board space. Ensure the application voltage does not exceed the -40 V rating and that the load current remains within the -100 mA limit for reliable operation.

Part Context

The FJX4012R series serves as a complement to the NPN FJX3012R, providing a matched pair option for complementary switching designs. This family of resistors-built-in transistors simplifies the design of logic interface and driver stages by integrating the necessary base biasing directly into the semiconductor package.

Replacement Considerations

The datasheet identifies the FJX3012R as a complementary counterpart rather than a direct substitute. Verify pinout compatibility if replacing with other PNP BRTs. No specific alternative part numbers are listed in the provided documentation.