MMBF4119

Overview

The MMBF4119 is an N-Channel Junction Field-Effect Transistor (JFET) switch manufactured by onsemi, formerly Fairchild Semiconductor. It is housed in a SOT-23 3L surface-mount package with interchangeable source and drain terminals. The device features a Drain-Gate Voltage rating of 40 V and a Gate-Source Voltage rating of -40 V. Electrical characteristics include a Gate Reverse Current of -10 pA at VGS = -20 V, a Gate-Source Cut-Off Voltage ranging from -2.0 V to -6.0 V, and a Zero-Gate Voltage Drain Current between 200 µA and 600 µA at VDS = 10 V. Small signal parameters specify a Common-Source Forward Transconductance of 100 µmhos to 330 µmhos and an Input Capacitance of 3.0 pF.

Feature Summary

• Designed for low current DC and audio applications
• Provides excellent performance as input stages for sub-picoamp instrumentation
• Suitable for high impedance signal sources

Applications

• Low current DC switching
• Audio circuit applications
• Input stages for sub-picoamp instrumentation
• High impedance signal sources

Procurement Notes

Verify the specific part number against official onsemi documentation, as historical Fairchild Semiconductor orderable part numbers may have been updated during integration. Confirm that the component meets all required absolute maximum ratings for your specific application environment. Ensure compliance with RoHS directives if applicable to your manufacturing standards. Validate all operating parameters through customer technical experts prior to final implementation.

Selection Notes

Select the MMBF4119 when designing circuits requiring low leakage and high input impedance for sensitive signal paths. Compare its Zero-Gate Voltage Drain Current and Cut-Off Voltage specifications against other JFET options to ensure compatibility with your biasing requirements. Consider the thermal resistance and power dissipation limits relative to your PCB layout and ambient temperature conditions.

Part Context

The MMBF4119 belongs to a family of N-Channel Switches that includes the MMBF4117 and MMBF4118. These devices are sourced from process 53 and share the same SOT-23 3L package form factor. While they share similar structural characteristics, each variant offers distinct electrical parameter ranges, particularly regarding gate cut-off voltage and drain current, allowing for tailored selection based on specific circuit needs.

Replacement Considerations

The MMBF4117 and MMBF4118 are direct functional equivalents within the same product family. Verify that the specific electrical tolerances of these alternatives align with your design requirements before substitution.