1N5259B Zener Diode Equivalent & Substitute Parts

Part Overview

The 1N5259B is a through-hole zener diode rated at 39 V nominal voltage with 500 mW power dissipation capability, packaged in the DO-35 axial configuration. Originally manufactured by SMC Diode Solutions, this component is classified as obsolete. The 1N5259B serves voltage regulation and protection applications requiring stable zener reference characteristics at 39 V.

Due to the obsolete status of the original SMC Diode Solutions part, identifying active equivalent components is necessary to maintain design continuity and ensure supply chain availability for new production and repair applications.

Substiute Parts

1N5259B

SMC Diode SolutionsIn Stock: 81951N5259B Datasheet

Current PartRFQ

1N5259B TR PBFREE

Central Semiconductor CorpIn Stock: 106401N5259B TR PBFREE Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1N5259B is determined by electrical and mechanical parameter equivalence within the zener diode category. The following parameters establish substitution validity:

Electrical Parameters (Critical):

• Zener voltage: 39 V nominal
• Tolerance: ±5%
• Maximum power dissipation: 500 mW
• Maximum impedance: 80 Ohms
• Reverse leakage current: 100 nA specification
• Forward voltage: 1.1 V maximum at 200 mA

Mechanical Parameters (Critical):

• Mounting type: Through Hole
• Package configuration: DO-35 axial
• Moisture sensitivity: MSL 1 (Unlimited)

The substitute part 1N5259B TR PBFREE meets all electrical specifications and maintains identical mechanical compatibility. The primary distinction is product status: the substitute is active and available, whereas the original is obsolete. The substitute also includes RoHS3 compliance certification and an extended operating temperature range.

Parameter Comparison

Engineering Selection Recommendations

The 1N5259B TR PBFREE manufactured by Central Semiconductor Corp is a direct functional equivalent to the obsolete 1N5259B from SMC Diode Solutions. Both components share identical electrical specifications across all critical parameters: 39 V zener voltage, ±5% tolerance, 500 mW power rating, 80 Ohms maximum impedance, and 100 nA reverse leakage current.

The substitute part provides additional advantages for new designs and production applications:

Product Status: The 1N5259B TR PBFREE maintains active production status with confirmed inventory availability, eliminating supply chain risk associated with the obsolete original part.

Compliance Certifications: The substitute is ROHS3 compliant, meeting current environmental and material restriction requirements. Both parts maintain REACH Unaffected status and EAR99 export classification.

Mechanical Compatibility: Identical DO-35 axial through-hole packaging ensures direct board-level substitution without layout modifications or mechanical redesign.

Operating Range: The substitute specifies an extended operating temperature range of —65°C to 200°C, providing broader thermal performance documentation compared to the original part.

For applications requiring the 1N5259B zener diode, the 1N5259B TR PBFREE is the appropriate active substitute that maintains full electrical and mechanical compatibility while ensuring continued supply availability.

Frequently Asked Questions (FAQ)

Q: Can the 1N5259B TR PBFREE be used as a direct replacement for the 1N5259B in existing designs?

A: Yes. Both components share identical electrical specifications (39 V zener voltage, ±5% tolerance, 500 mW power dissipation, 80 Ohms impedance) and mechanical packaging (DO-35 axial through-hole). No circuit modifications or board redesign is required.

Q: What is the significance of the "TR PBFREE" designation in the substitute part number?

A: The "TR" designation indicates tape reel packaging format (Cut Tape), and "PBFREE" indicates lead-free (RoHS compliant) construction. These designations reflect manufacturing and environmental compliance standards but do not affect electrical performance or functional compatibility.

Q: Are there differences in reverse leakage current specifications between the two parts?

A: Both parts specify 100 nA maximum reverse leakage current. The original part specifies this value at 29 V, while the substitute specifies it at 30 V. This minor difference in measurement voltage does not affect functional equivalence or circuit performance.

Q: Does the RoHS3 compliance of the substitute part affect compatibility with existing designs?

A: No. RoHS3 compliance indicates adherence to material restriction directives and reflects current manufacturing standards. The electrical and mechanical characteristics remain identical, ensuring full compatibility with existing circuit designs.

Q: What is the operating temperature range for the 1N5259B TR PBFREE?

A: The substitute part operates across —65°C to 200°C. This range encompasses typical industrial and commercial applications. Verify that your specific application requirements fall within this range.

Q: Can the 1N5259B TR PBFREE be used in both new production and repair applications?

A: Yes. The active product status and confirmed inventory availability of the 1N5259B TR PBFREE make it suitable for new production designs, manufacturing runs, and field repair applications requiring replacement of obsolete 1N5259B components.

Q: Are there any packaging considerations when substituting these parts?

A: Both components use identical DO-35 axial through-hole packaging. No modifications to PCB footprints, lead spacing, or mounting procedures are required. The parts are mechanically and electrically interchangeable at the board level.