SMP4391

Overview

The SMP4391 is an N-channel JFET utilizing InterFET's N0132S geometry, housed in a SOT-23 surface-mount package. It features a gate-to-source breakdown voltage of -40 V and a drain-to-source saturation current (IDSS) ranging from 50 mA to 150 mA. The device exhibits a gate-to-source cutoff voltage between -4 V and -10 V. Static on-resistance is specified between 30 Ω and 60 Ω at 1 kHz. Dynamic characteristics include an input capacitance of 14 pF and turn-on delay times up to 15 ns.

Feature Summary

• Utilizes InterFET N0132S geometry for optimized performance
• Provides low noise operation with typical specifications of 1.2 nV/√Hz
• Designed for fast switching applications with minimal delay times
• Offers low gate leakage currents typically below 50 pA at room temperature

Applications

• Low on-resistance analog switches
• Chopper circuits
• Commutator designs

Procurement Notes

Verify the specific suffix against the official datasheet to confirm packaging type. The SMP4391 designation corresponds to the standard bulk SOT-23 configuration. Alternative suffixes such as TR indicate tape and reel options with defined piece counts. Ensure the selected variant matches the required manufacturing process and handling constraints for the intended assembly line.

Selection Notes

Select this component when low noise and fast switching are critical requirements. The N0132S geometry supports high-speed operation suitable for precision analog switching. Consider the IDSS range of 50 mA to 150 mA for circuit biasing. The SOT-23 package facilitates automated surface-mount assembly while maintaining electrical performance comparable to through-hole variants.

Part Context

This part belongs to the 2N4391-2-3 family of N-channel JFETs designed for switch, chopper, and commutator applications. The series includes through-hole TO-18 and TO-92 versions alongside surface-mount SOT-23 options. All variants share similar electrical characteristics but differ in physical packaging and thermal dissipation capabilities.

Replacement Considerations

Direct substitutes within the same family include SMP4392 and SMP4393. These alternatives offer different IDSS and VGS(off) ranges while maintaining identical package dimensions and pinouts. Verify that the alternative cutoff voltage and saturation current meet the specific circuit design requirements.