2N4339

Jfets Overview

The Vishay Siliconix 2N4339 is an N-channel Junction Field-Effect Transistor (JFET) housed in a hermetically sealed TO-206AA (TO-18) package. It features a Gate-Source Cutoff Voltage (VGS(off)) ranging from -0.6 V to -1.8 V and a minimum Gate-Source Breakdown Voltage of -50 V. The device exhibits a typical forward transconductance of 0.8 mS with a maximum saturation drain current of 1.5 mA. Designed for low-noise applications, it offers an equivalent input noise voltage of 6 nV/√Hz at 1 kHz.

Jfets Feature Summary

• Hermetically sealed metal case construction suitable for military processing
• Low cutoff voltage enabling operation with low-level power supplies
• Very low noise characteristics for high-sensitivity signal amplification
• High input impedance ensuring minimal loading on preceding stages

Jfets Applications

• High-gain, low-noise amplifier circuits
• Infrared detector pre-amplifiers
• Ultrahigh input impedance pre-amplifier stages
• Low-current, low-voltage battery-powered amplifiers

Jfets Procurement Notes

Verify the specific revision status of the datasheet against the manufacturer's official records before finalizing design specifications. Confirm that the TO-206AA package dimensions align with the target PCB footprint requirements. Ensure that the supply chain source provides genuine Vishay Siliconix components to maintain guaranteed electrical performance parameters.

Jfets Selection Notes

Select this component when circuit designs require a JFET with a very low gate-source cutoff voltage to accommodate limited supply rails. The TO-18 package is appropriate for applications demanding hermetic sealing or high thermal stability. Compare the 1.5 mA maximum IDSS against system biasing needs to ensure proper operating point selection within the specified -0.6 V to -1.8 V range.

Jfets Part Context

This part belongs to the Vishay Siliconix 2N4338/4339/4340/4341 series of N-channel JFETs. The series is engineered for sensitive amplifier stages at low to mid-frequencies. While sharing similar packaging and basic topology, the 2N4339 is distinguished by its specific intermediate cutoff voltage range compared to the lower threshold of the 2N4338 and higher thresholds of the 2N4340 and 2N4341.

Jfets Replacement Considerations

Direct pin-compatible replacements within the same family include the 2N4338, 2N4340, and 2N4341. Verify that the alternative part's VGS(off) range matches the circuit's biasing constraints. For surface-mount requirements, consider the SST201 series devices which offer similar electrical characteristics in TO-226AA or SOT-23 packages.