IF140ST3

Overview

The IF140ST3 is an N-Channel Junction Field-Effect Transistor (JFET) manufactured by InterFET, utilizing the proprietary N0014L geometry. It is housed in a Surface Mount SOT-23 package and operates with a maximum continuous power dissipation of 350 mW at 25°C. The device features a gate-to-source breakdown voltage of -20 V and a typical drain-to-source saturation current (IDSS) of 10 mA. Key electrical characteristics include a forward transconductance (GFS) of 3.5 mS, input capacitance (Ciss) of 3 pF, and reverse transfer capacitance (Crss) of 1.2 pF. Gate leakage is typically 100 fA at 25°C, and the equivalent input noise voltage is approximately 3 nV/√Hz at 10 Hz.

Feature Summary

• Utilizes InterFET N0014L geometry to achieve exceptionally low gate leakage currents and minimal input capacitance for high-frequency performance.
• Provides high radiation tolerance suitable for demanding military and aerospace environments.
• Offers flexible packaging options including surface mount SOT-23, through-hole TO-72, and bare die configurations.

Applications

• Medical imaging systems and ultrasound equipment requiring low-noise signal amplification
• Military radar, satellite communications, and missile guidance systems
• Hydrophone preamplifiers and medical monitoring/recording devices

Procurement Notes

Verify the specific ordering suffix when purchasing, as it determines the physical package type and shipping configuration. Options include bulk SOT-23 (IF140ST3), tape and reel formats (IF140ST3TR), through-hole TO-72, and chip trays. Confirm compliance requirements such as RoHS and REACH status directly with the manufacturer or authorized distributor prior to finalizing procurement orders.

Selection Notes

Select the IF140ST3 variant when a compact surface-mount footprint is required for low-noise amplifier designs. Ensure the design accommodates the 350 mW power dissipation limit and the -20 V gate-source voltage rating. Consider the IF140T72 if through-hole mounting is necessary, or evaluate custom binning options if tighter parameter tolerances are required for specific production batches.

Part Context

The IF140ST3 belongs to the IF140 family of mid-gain N-Channel JFETs designed for low-leakage applications. This series targets high-frequency and low-noise circuits where standard silicon JFETs may exhibit higher leakage or capacitance. The product line includes various package styles to support diverse manufacturing needs across industrial, medical, and defense sectors.

Replacement Considerations

Officially documented industry standard cross-compatibility includes MMBF4416, BF512, SST4416, SST4416A, MMBF4416A, MMBF5485, and SSTJ211. Verify pinout compatibility and ensure that the substitute component meets the specific leakage and capacitance requirements of the original circuit design before implementation.

FAQ

What is the typical gate leakage current for the IF140ST3?

The typical gate leakage current is 100 fA at room temperature (25°C).

Are the source and drain pins interchangeable on the SOT-23 package?

Yes, the datasheet notes that the Source and Drain pins are interchangeable on the SOT-23 package.

What is the maximum operating junction temperature for the SOT-23 version?

The maximum operating junction temperature for the SOT-23 package is 150°C.