1N5255B Zener Diode Equivalent & Substitute Parts

Part Overview

The 1N5255B is a 28 V, 500 mW Zener diode in DO-35 axial through-hole packaging manufactured by onsemi. This component is classified as obsolete, necessitating identification of active equivalent and substitute parts for ongoing design requirements and production continuity. Substitute parts must maintain electrical performance within specified tolerances while meeting current manufacturing and compliance standards.

Substiute Parts

1N5255B

onsemiIn Stock: 22051N5255B Datasheet

Current PartRFQ

1N5362BRLG

onsemiIn Stock: 15421N5362BRLG Datasheet

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1N5255A

Microchip TechnologyIn Stock: 8061N5255A Datasheet

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1N5255B TR PBFREE

Central Semiconductor CorpIn Stock: 219251N5255B TR PBFREE Datasheet

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1N5255B-TR

Vishay General Semiconductor - Diodes DivisionIn Stock: 508391N5255B-TR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1N5255B is determined by the following critical parameters:

Electrical Compatibility Criteria:

• Zener voltage (Vz): 28 V nominal
• Tolerance: ±5% or tighter
• Power dissipation: 500 mW minimum
• Impedance (Zzt): 44 Ohms maximum
• Reverse leakage current: 100 nA @ 21 V maximum
• Forward voltage: 1.2 V @ 200 mA maximum

Mechanical Compatibility Criteria:

• Mounting type: Through Hole
• Package / Case: DO-35 or equivalent axial configuration

Compliance Criteria:

• REACH Status: REACH Unaffected
• ECCN: EAR99

Substitute parts are grouped into two categories:

Category 1: Direct Electrical Equivalents (500 mW Power Rating) Parts maintaining identical electrical specifications and 500 mW power rating with DO-35 packaging.

Category 2: Higher Power Alternative (5 W Power Rating) Parts with identical zener voltage and tolerance but increased power dissipation capability, suitable for applications requiring higher thermal margin.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Equivalents):

1N5255B-TR (Vishay General Semiconductor - Diodes Division)

• Maintains all electrical specifications of the original 1N5255B
• Active product status with 50,809 units in stock
• ROHS3 compliant
• AEC-Q101 automotive qualification
• Operating temperature range: -65 to 175°C (5°C reduction from original)
• Suitable for automotive and industrial applications

1N5255B TR PBFREE (Central Semiconductor Corp)

• Maintains all electrical specifications of the original 1N5255B
• Active product status with 21,833 units in stock
• ROHS3 compliant
• Operating temperature range: -65 to 200°C (matches original)
• Lead-free construction
• Suitable for consumer and industrial applications

Secondary Substitute (Tighter Tolerance):

1N5255A (Microchip Technology)

• Maintains electrical specifications with wider tolerance (±10% vs. ±5%)
• Active product status with 792 units in stock
• RoHS non-compliant
• Operating temperature range: -65 to 175°C
• Forward voltage specification: 1.5 V @ 200 mA (higher than original 1.2 V)
• Selection requires tolerance verification for application requirements

Higher Power Alternative:

1N5362BRLG (onsemi)

• Identical zener voltage and tolerance (28 V, ±5%)
• Increased power dissipation: 5 W (10× original rating)
• Reduced impedance: 6 Ohms (vs. 44 Ohms)
• Active product status with 1,468 units in stock
• ROHS3 compliant
• Operating temperature range: -65 to 200°C
• Selection appropriate for applications requiring higher thermal margin or increased current handling

Frequently Asked Questions (FAQ)

Q: Can 1N5255B-TR be used as a direct replacement for 1N5255B?

A: Yes. The 1N5255B-TR maintains identical electrical specifications including 28 V zener voltage, ±5% tolerance, 500 mW power rating, 44 Ohms impedance, and 100 nA reverse leakage current. Both use DO-35 through-hole packaging. The operating temperature range is reduced from -65 to 200°C to -65 to 175°C. AEC-Q101 automotive qualification is an additional benefit.

Q: What is the difference between 1N5255B TR PBFREE and 1N5255B-TR?

A: Both parts maintain identical electrical specifications and 500 mW power rating. The primary differences are manufacturer (Central Semiconductor Corp vs. Vishay), packaging format (Cut Tape vs. Cut Tape), and operating temperature range (1N5255B TR PBFREE extends to 200°C while 1N5255B-TR is limited to 175°C). The 1N5255B TR PBFREE designation indicates lead-free construction.

Q: Why does 1N5255A have a ±10% tolerance instead of ±5%?

A: The 1N5255A is manufactured by Microchip Technology with a wider tolerance specification. This affects zener voltage accuracy. Applications requiring tighter voltage regulation should verify compatibility with the ±10% tolerance before selection.

Q: When should 1N5362BRLG be selected over 1N5255B equivalents?

A: The 1N5362BRLG provides 5 W power dissipation versus 500 mW in the original 1N5255B. Selection is appropriate for applications requiring higher thermal margin, increased current handling capability, or where circuit design benefits from lower impedance (6 Ohms vs. 44 Ohms). Mechanical package differs (T-18 Axial vs. DO-35).

Q: Are all substitute parts REACH compliant?

A: Yes. All listed substitute parts maintain REACH Unaffected status, matching the original 1N5255B.

Q: What packaging considerations apply to these substitutes?

A: The 1N5255B, 1N5255B-TR, 1N5255B TR PBFREE, and 1N5255A all use DO-35 (DO-204AH) axial through-hole packaging with identical mechanical dimensions. The 1N5362BRLG uses T-18 axial packaging, which is physically larger and may require PCB layout modification.

Q: Is RoHS compliance a factor in substitute selection?

A: The 1N5255B-TR and 1N5255B TR PBFREE are ROHS3 compliant. The 1N5255A is RoHS non-compliant. The 1N5362BRLG is ROHS3 compliant. Selection depends on end-product regulatory requirements.