SMPJ305TR

Overview

The SMPJ305TR is an N-Channel Junction Field Effect Transistor (JFET) manufactured by InterFET, packaged in SOT23 and supplied in tape and reel format. It utilizes the InterFET N0026S geometry to deliver low noise performance with a typical input capacitance of 4.3pF and low leakage current of 10pA. The device features a Gate-to-Source Breakdown Voltage of -30V, a Drain-to-Source Saturation Current minimum of 1mA, and a Gate-to-Source Cutoff Voltage ranging from -0.5V to -3V. Forward transconductance is specified at a minimum of 3000μS.

Feature Summary

• Utilizes InterFET N0026S geometry for optimized RF performance
• Provides low noise characteristics suitable for sensitive signal processing
• Exhibits extremely low gate leakage current for high impedance stability
• Offers low input capacitance to minimize signal attenuation at high frequencies

Applications

• Mixers
• Oscillators
• VHF/UHF Amplifiers

Procurement Notes

Verify that the specific ordering suffix TR corresponds to the Tape and Reel packaging configuration rather than bulk shipping. Confirm the manufacturer is InterFET, as other vendors may produce similar J305 variants with different electrical tolerances or pinouts. Ensure the component meets RoHS compliance requirements if mandated by the end application standards. Cross-reference the datasheet revision IF35033.R00 to ensure alignment with current manufacturing specifications.

Selection Notes

Select this component when designing circuits requiring low noise figures and minimal input capacitance for VHF or UHF frequency ranges. The -30V breakdown voltage rating supports standard biasing configurations while maintaining high input impedance. Consider the SOT23 package constraints regarding thermal dissipation and physical footprint compared to through-hole alternatives. Evaluate the forward transconductance specifications against the required gain and linearity targets for the specific amplifier or mixer topology.

Part Context

The SMPJ305TR belongs to the J304/J305 family of N-Channel JFETs designed specifically for radio frequency applications. These devices are engineered to address the demands of modern communication systems where signal integrity and low distortion are critical. The SMT variant allows for automated assembly processes, supporting high-volume production environments while maintaining the electrical performance characteristics associated with the broader J305 series.

Replacement Considerations

The J305 is the direct through-hole equivalent to the SMPJ305 surface mount device. Other manufacturers may offer generic J305 replacements, but electrical parameters such as IDSS and VGSOFF may vary significantly. Verify pinout compatibility and absolute maximum ratings before substituting components from different suppliers.