2N4392 JFET N-Channel Transistor Equivalent & Substitute Parts

Part Overview

The 2N4392 is an N-Channel JFET transistor manufactured by Vishay Siliconix, designed for through-hole applications in the TO-206AA (TO-18) metal can package. This device operates at a maximum breakdown voltage of 40 V with a maximum power dissipation of 1.8 W and an operating temperature range of -65°C to 200°C. The 2N4392 is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing design support and component procurement.

Substiute Parts

2N4392

Vishay SiliconixIn Stock: 70942N4392 Datasheet

Current PartRFQ

2N4858A

Central Semiconductor CorpIn Stock: 14842N4858A Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N4392 is determined by electrical and mechanical compatibility across the following critical parameters:

• Voltage - Breakdown (V(BR)GSS): Must equal or exceed 40 V
• FET Type: Must be N-Channel
• Mounting Type: Must be Through Hole
• Package / Case: Must be compatible with TO-206AA or TO-18-3 Metal Can
• Operating Temperature Range: Must support -65°C to 200°C
• Resistance - RDS(On): Must equal 60 Ohms

The 2N4858A qualifies as a manufacturer-recommended substitute based on matching these core electrical and mechanical specifications. While the 2N4858A exhibits lower maximum power dissipation (360 mW versus 1.8 W) and different drain current characteristics, it maintains electrical equivalence in voltage ratings, on-resistance, and package compatibility.

Parameter Comparison

Engineering Selection Recommendations

The 2N4858A is the manufacturer-recommended substitute for the obsolete 2N4392. Selection of this substitute is supported by the following factors:

• Electrical equivalence in voltage breakdown rating (40 V), on-resistance (60 Ohms), and operating temperature range (-65°C to 200°C)
• Identical through-hole mounting configuration and TO-18 metal can package compatibility
• Active product status, ensuring ongoing availability and supply chain continuity
• ROHS3 compliance, meeting current environmental and regulatory requirements
• Manufacturer recommendation from Central Semiconductor Corp

The 2N4858A is suitable for applications where the 2N4392 was previously specified, provided that circuit design accommodates the lower maximum power dissipation rating (360 mW versus 1.8 W). Applications requiring the full 1.8 W power capability of the original 2N4392 must evaluate thermal management and power budget constraints with the substitute device.

Frequently Asked Questions (FAQ)

Q: Can the 2N4858A directly replace the 2N4392 in existing designs?

A: The 2N4858A provides electrical equivalence in voltage rating, on-resistance, and package configuration. However, the reduced maximum power dissipation (360 mW versus 1.8 W) must be evaluated against circuit power requirements. If the original design operates below 360 mW, direct substitution is feasible.

Q: What are the key differences between these two parts?

A: The primary differences are maximum power dissipation, drain current characteristics, and product status. The 2N4858A has lower Idss (8 mA @ 15 V versus 25 mA @ 20 V) and lower input capacitance (10 pF @ 10 V versus 14 pF @ 20 V). The 2N4858A is an active product with ROHS3 compliance, while the 2N4392 is obsolete and RoHS non-compliant.

Q: Are the packages physically identical?

A: Both devices use the TO-206AA (TO-18-3 Metal Can) through-hole package. Physical compatibility is confirmed, allowing direct socket substitution without PCB modification.

Q: Does the 2N4858A meet current regulatory requirements?

A: Yes. The 2N4858A is ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory standards. The 2N4392 is RoHS non-compliant.

Q: What applications are suitable for the 2N4858A?

A: The 2N4858A is suitable for low-power N-Channel JFET applications operating at 40 V or below, including amplification, switching, and signal conditioning circuits where power dissipation does not exceed 360 mW.