2N4093 JFET N-Channel Transistor Equivalent & Substitute Parts

Part Overview

The 2N4093 is a JFET N-Channel transistor rated for 40 V operation with 360 mW power dissipation in a TO-18 through-hole package. This device is manufactured by Microchip Technology and is currently discontinued at DiGi Electronics, necessitating identification of functionally equivalent alternatives for ongoing design and repair applications. The part remains available in inventory (1472 pcs) despite its discontinued status, making substitution evaluation critical for long-term component sourcing strategy.

Substiute Parts

2N4093

Microchip TechnologyIn Stock: 15362N4093 Datasheet

Current PartRFQ

2N4858A

Central Semiconductor CorpIn Stock: 14842N4858A Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 2N4093 is determined by strict equivalence across the following critical parameters:

Mandatory Equivalence Criteria:

• FET Type: N-Channel (functional polarity requirement)
• Drain to Source Voltage (Vdss): 40 V minimum (voltage rating compatibility)
• Voltage - Breakdown (V(BR)GSS): 40 V minimum (gate-source protection)
• Power - Max: 360 mW minimum (thermal dissipation capacity)
• Package / Case: TO-206AA, TO-18-3 Metal Can (physical and electrical pinout compatibility)
• Mounting Type: Through Hole (assembly method compatibility)

Performance Parameters Evaluated:

• Current - Drain (Idss): Saturation current characteristics
• Resistance - RDS(On): On-state conduction characteristics
• Operating Temperature Range: Thermal operating envelope

The 2N4858A manufactured by Central Semiconductor Corp meets all mandatory equivalence criteria and qualifies as a direct substitute for the 2N4093.

Parameter Comparison

Engineering Selection Recommendations

2N4858A (Central Semiconductor Corp) - Primary Substitute

The 2N4858A is a direct functional equivalent to the 2N4093 with the following engineering considerations:

• Voltage Ratings: Identical Vdss (40 V) and V(BR)GSS (40 V) ratings ensure circuit voltage compatibility without modification.
• Power Dissipation: Equivalent 360 mW maximum power rating maintains thermal design margins.
• On-State Resistance: The 2N4858A exhibits lower RDS(On) (60 Ohms vs. 80 Ohms), resulting in reduced conduction losses and improved efficiency in switching applications.
• Temperature Range: Extended operating range (-65°C to 200°C vs. -65°C to 175°C) provides additional thermal margin for high-temperature applications.
• Product Status: The 2N4858A is Active, ensuring continued availability and supply chain reliability compared to the discontinued 2N4093.
• Compliance: The 2N4858A is ROHS3 Compliant, meeting current environmental and regulatory requirements. The 2N4093 is RoHS non-compliant.
• Packaging: Identical TO-18 through-hole package ensures direct PCB footprint compatibility without layout modification.

The 2N4858A is suitable for direct substitution in all applications where the 2N4093 was originally specified.

Frequently Asked Questions (FAQ)

Q: Can the 2N4858A be used as a direct replacement for the 2N4093 without circuit modification?

A: Yes. The 2N4858A meets all mandatory equivalence criteria: identical N-Channel FET type, 40 V voltage ratings, 360 mW power rating, and TO-18 through-hole package. Direct substitution is supported without circuit redesign.

Q: What is the significance of the lower RDS(On) value in the 2N4858A?

A: The 2N4858A exhibits 60 Ohms on-state resistance compared to 80 Ohms in the 2N4093. This lower resistance reduces conduction losses during the on-state, resulting in lower heat generation and improved circuit efficiency. This represents a performance improvement over the original part.

Q: Are there differences in the saturation drain current (Idss) specifications?

A: The Idss specifications are measured at different Vds conditions: 2N4093 at 20 V and 2N4858A at 15 V. Both devices specify 8 mA saturation current. The different measurement conditions reflect standard datasheet practices but do not affect substitution compatibility.

Q: What is the impact of the extended temperature range in the 2N4858A?

A: The 2N4858A operates to 200°C junction temperature compared to 175°C for the 2N4093. This extended range provides additional thermal margin for applications operating at elevated temperatures or with high ambient conditions, representing an operational advantage.

Q: Is the 2N4858A packaging identical to the 2N4093?

A: Yes. Both devices use the TO-206AA, TO-18-3 Metal Can package with through-hole mounting. PCB footprints, lead spacing, and pinout are identical, enabling direct component substitution without layout modification.

Q: What compliance differences exist between these parts?

A: The 2N4858A is ROHS3 Compliant, while the 2N4093 is RoHS non-compliant. For applications subject to RoHS regulations or environmental compliance requirements, the 2N4858A is the appropriate selection.

Q: Why is the 2N4093 discontinued if the 2N4858A is available?

A: Component discontinuation reflects manufacturer production decisions and market demand. The 2N4858A remains in active production by Central Semiconductor Corp, ensuring continued availability for new designs and replacement applications.