2N4338

Jfets Overview

The Vishay Siliconix 2N4338 is an N-channel Junction Field-Effect Transistor (JFET) housed in a hermetically sealed TO-206AA (TO-18) metal can package. It features a Gate-Source Cutoff Voltage (VGS(off)) ranging from -0.3 V to -1 V and a minimum Gate-Source Breakdown Voltage of -50 V. The device exhibits a typical forward transconductance (gfs) of 0.6 mS at 1 kHz, with a maximum saturation drain current (IDSS) of 0.6 mA. Designed for low-noise applications, it offers an equivalent input noise voltage of 6 nV/√Hz.

Jfets Feature Summary

• Hermetically sealed TO-206AA (TO-18) metal case construction suitable for military processing
• Low cutoff voltage design accommodating low-level power supplies down to 1 V
• Very low noise characteristics with high-quality low-level signal amplification capabilities
• High input impedance ensuring minimal system error and low signal loss

Jfets Applications

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

Jfets Procurement Notes

Verify the specific lot traceability and military processing requirements against the datasheet specifications before procurement. Confirm that the TO-206AA package dimensions align with the target PCB or chassis mounting constraints. Ensure the supply chain provides documentation confirming the hermetic seal integrity required for sensitive environments.

Jfets Selection Notes

Select the 2N4338 when the application demands the lowest possible gate-source cutoff voltage within the JFET family to facilitate operation at extremely low supply voltages. This component is appropriate for circuits prioritizing minimal noise figure and high input impedance over high current handling capacity. Evaluate thermal derating requirements carefully as the power dissipation limit is restricted to 300 mW.

Jfets Part Context

This component belongs to the Vishay Siliconix 2N4338/4339/4340/4341 series of N-channel JFETs designed for sensitive amplifier stages at low to mid-frequencies. While other parts in this series offer higher cutoff voltages and currents, the 2N4338 is specifically optimized for the lowest voltage threshold (-0.3 V to -1 V), making it distinct for ultra-low voltage biasing scenarios.

Jfets Replacement Considerations

For similar products in different packages, refer to the J/SST201 series data sheet which covers TO-226AA (TO-92) and TO-236 (SOT-23) variants. Direct pin-compatible replacements in the same TO-18 package should be sourced from official Vishay cross-reference lists to ensure electrical parameter matching.

Jfets FAQ

What is the maximum allowable gate-source breakdown voltage for the 2N4338?

The minimum Gate-Source Breakdown Voltage (V(BR)GSS) is specified as -50 V under test conditions of IG = -1 µA and VDS = 0 V.

Is the 2N4338 suitable for high-frequency RF applications?

No, the datasheet specifies the device is designed for sensitive amplifier stages at low- to mid-frequencies, with dynamic parameters typically measured at 1 kHz.

How does the package type affect the device's environmental resilience?

The TO-206AA (TO-18) package is hermetically sealed, making the component suitable for military processing and harsh environmental conditions compared to plastic-sealed alternatives.