J108_D26Z Equivalent & Substitute Parts

Part Overview

The J108_D26Z is an N-Channel JFET transistor manufactured by onsemi, rated for 25 V breakdown voltage with 625 mW power dissipation in a through-hole TO-92-3 package. This device is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity. Substitute parts must maintain electrical equivalence across critical parameters including breakdown voltage, drain current characteristics, and thermal operating range while accommodating different packaging technologies.

Substiute Parts

J108_D26Z

onsemiIn Stock: 792J108_D26Z Datasheet

Current PartRFQ

MMBFJ108

onsemiIn Stock: 1197MMBFJ108 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the J108_D26Z is determined by strict equivalence across electrical characteristics and thermal specifications. The following parameters establish substitution validity:

• FET Type: Must be N-Channel JFET
• Voltage - Breakdown (V(BR)GSS): Must equal 25 V
• Current - Drain (Idss): Must equal 80 mA @ 15 V
• Voltage - Cutoff (VGS off): Must equal 3 V @ 10 nA
• Resistance - RDS(On): Must equal 8 Ohms
• Operating Temperature Range: Must span -55°C to 150°C (TJ)

The MMBFJ108 meets all electrical parameter requirements. The primary distinction is packaging: MMBFJ108 uses surface-mount SOT-23-3 technology versus the through-hole TO-92-3 of the J108_D26Z. Power rating differs (350 mW vs. 625 mW); applications requiring the full 625 mW dissipation cannot use MMBFJ108 without thermal management modifications.

Parameter Comparison

Engineering Selection Recommendations

MMBFJ108 is the direct electrical equivalent for J108_D26Z applications. Selection between these parts depends on design constraints:

• Through-hole requirement: J108_D26Z remains the only option if PCB layout mandates through-hole mounting.
• Surface-mount design: MMBFJ108 is preferred due to active product status and current manufacturing availability (1106 pcs in stock vs. 725 pcs for obsolete J108_D26Z).
• Power dissipation: Applications requiring sustained operation at or near 625 mW must verify that MMBFJ108's 350 mW rating is adequate. Thermal analysis is required if power dissipation approaches or exceeds 350 mW.
• Compliance: Both parts carry identical REACH and ECCN classifications (REACH Unaffected, EAR99). MMBFJ108 is RoHS3 compliant; J108_D26Z compliance status is not specified.

Frequently Asked Questions (FAQ)

Q: Can MMBFJ108 directly replace J108_D26Z in existing through-hole designs?

A: Electrical substitution is valid. Physical replacement requires PCB redesign to accommodate SOT-23-3 surface-mount footprint. Through-hole to surface-mount conversion involves layout changes and assembly process modifications.

Q: What is the impact of the 275 mW power rating difference?

A: MMBFJ108 has 350 mW maximum power dissipation versus 625 mW for J108_D26Z. In applications where the device dissipates less than 350 mW, no impact occurs. For higher dissipation, thermal management (heatsinking, reduced duty cycle, or circuit redesign) is necessary to maintain junction temperature within the -55°C to 150°C operating range.

Q: Are there other N-Channel JFET alternatives with identical electrical parameters?

A: Based on provided data, MMBFJ108 is the only listed substitute meeting all electrical parameter requirements (25 V breakdown, 80 mA Idss, 3 V VGS off, 8 Ohms RDS(On)).

Q: What is the moisture sensitivity level for both parts?

A: Both J108_D26Z and MMBFJ108 carry MSL 1 (Unlimited), indicating no moisture sensitivity restrictions for storage or handling.

Q: Is MMBFJ108 suitable for military or aerospace applications?

A: Both parts are classified as EAR99 (no export restrictions). Aerospace and military qualification requirements are not specified in the provided data and must be verified against application-specific standards.