SMP4393

Overview

The InterFET SMP4393 is an N-Channel JFET utilizing the proprietary N0132S geometry, designed for low-noise and fast-switching applications. It features a Gate to Source Breakdown Voltage (BV_GSS) of -40V and a Drain to Source Saturation Current (I_DSS) ranging from 5mA to 30mA. The device exhibits a Gate to Source Cutoff Voltage (V_GS(off)) between -0.5V and -3V, with typical gate leakage below 50pA at room temperature. Static on-resistance (R_DS(on)) is specified between 30Ω and 100Ω at 1kHz. Dynamic characteristics include an input capacitance of 14pF and turn-on delay times around 15ns.

Feature Summary

• Utilizes InterFET N0132S geometry for optimized performance
• Provides low noise operation with typical 1.2 nV/√Hz specification
• Features fast switching capabilities suitable for high-speed designs
• Offers extremely low cutoff voltage ideal for low-level power supplies

Applications

• Low On Resistance Analog Switches
• Chopper circuits
• Commutator designs

Procurement Notes

Verify the specific package variant required, as the SMP4393 designation covers both bulk SOT23 and tape-and-reel configurations. Confirm binning requirements for I_DSS and V_GS(off) parameters if tight tolerances are necessary for the application. Ensure compatibility with the chosen mounting style, whether surface mount or through-hole alternatives like TO-18 or TO-92 are preferred for the final assembly.

Selection Notes

Select the SMP4393 when a low cutoff voltage is critical for controlling low-level signals efficiently. The device's low gate leakage makes it suitable for precision analog switching where minimal bias current is required. Consider the dynamic capacitance values for high-frequency switching speeds and ensure the -40V breakdown rating aligns with the maximum circuit voltages to prevent device failure under transient conditions.

Part Context

The SMP4393 belongs to the 2N4391-2-3 family of N-Channel JFETs manufactured by InterFET. This series shares the same core semiconductor structure but differs in electrical parameter bins, specifically regarding saturation current and cutoff voltage ranges. The SMP prefix indicates the Surface Mount Technology (SMT) version housed in a SOT23 package, distinct from the through-hole TO-18 or TO-92 variants.

Replacement Considerations

Direct replacements within the same family include the SMP4391 and SMP4392, though their higher cutoff voltages may not suit low-voltage control applications. Cross-brand equivalents require careful verification of pinout compatibility and matching of BV_GSS and R_DS(on) specifications to ensure functional parity in existing circuit designs.