1N5545 Equivalent & Substitute Parts

Part Overview

The 1N5545 is an active Zener diode manufactured by Microchip Technology, classified as a voltage regulator component in the Diodes, Zener category. This through-hole device is rated for 30 V nominal Zener voltage with 500 mW maximum power dissipation and operates across a temperature range of -65°C to 175°C. The component is supplied in bulk packaging with DO-35 (DO-204AH) axial package configuration. Equivalent and substitute parts are identified to address inventory availability, packaging format requirements, or specific tolerance and performance specifications needed for circuit design applications.

Substiute Parts

1N5545

Microchip TechnologyIn Stock: 9171N5545 Datasheet

Current PartRFQ

1N5256B TR PBFREE

Central Semiconductor CorpIn Stock: 51561N5256B TR PBFREE Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1N5545 with the 1N5256B TR PBFREE is permissible based on the following critical parameters:

Matching Parameters:

• Voltage - Zener (Nom): Both rated at 30 V
• Power - Max: Both rated at 500 mW
• Voltage - Forward (Vf) (Max) @ If: Both 1.1 V @ 200 mA
• Mounting Type: Both Through Hole
• Package / Case: Both DO-204AH, DO-35, Axial

Differing Parameters:

• Tolerance: 1N5545 is ±20%; 1N5256B TR PBFREE is ±5% (tighter tolerance)
• Current - Reverse Leakage @ Vr: 1N5545 is 10 nA @ 24 V; 1N5256B TR PBFREE is 100 nA @ 23 V
• Operating Temperature: 1N5545 is -65°C ~ 175°C; 1N5256B TR PBFREE is -65°C ~ 200°C (extended upper range)
• Impedance (Max) (Zzt): 1N5256B TR PBFREE specifies 49 Ohms (not provided for 1N5545)

The 1N5256B TR PBFREE functions as a direct substitute where the core voltage regulation and power handling requirements are identical. The tighter tolerance specification of ±5% provides improved voltage accuracy compared to the ±20% tolerance of the 1N5545.

Parameter Comparison

Engineering Selection Recommendations

Both the 1N5545 and 1N5256B TR PBFREE are active products with identical REACH and ECCN compliance status. Selection between these components is determined by application-specific requirements:

Select 1N5545 when:

• Bulk packaging format is required for manufacturing operations
• The ±20% tolerance specification meets circuit design requirements
• Operating temperature range of -65°C to 175°C is sufficient

Select 1N5256B TR PBFREE when:

• Cut tape packaging format is required for automated assembly processes
• Tighter ±5% tolerance specification is necessary for voltage regulation accuracy
• Extended operating temperature range to 200°C is required
• RoHS3 compliance certification is mandated
• Lead-free (PBFREE) construction is specified

Both components satisfy identical core electrical parameters for 30 V, 500 mW Zener diode applications in DO-35 through-hole configurations.

Frequently Asked Questions (FAQ)

Q: Can the 1N5256B TR PBFREE directly replace the 1N5545 in existing circuit designs?

A: Yes. Both components share identical nominal Zener voltage (30 V), maximum power rating (500 mW), forward voltage characteristics (1.1 V @ 200 mA), and package configuration (DO-35 axial through-hole). The 1N5256B TR PBFREE provides improved voltage tolerance (±5% versus ±20%) and extended temperature range, making it functionally compatible for voltage regulation applications.

Q: What is the significance of the tolerance difference between ±20% and ±5%?

A: Tolerance specifies the allowable deviation from the nominal 30 V Zener voltage. The 1N5545 permits deviation between 24 V and 36 V, while the 1N5256B TR PBFREE permits deviation between 28.5 V and 31.5 V. Applications requiring precise voltage regulation benefit from the tighter ±5% tolerance of the 1N5256B TR PBFREE.

Q: Are there packaging differences between these components?

A: The 1N5545 is supplied in bulk packaging, while the 1N5256B TR PBFREE is supplied in cut tape (CT) packaging. Both use identical DO-35 (DO-204AH) axial package configuration for through-hole mounting. Packaging format selection depends on manufacturing process requirements: bulk for manual assembly or small-volume production, cut tape for automated pick-and-place assembly.

Q: What does PBFREE designation indicate?

A: PBFREE indicates lead-free construction, compliant with RoHS3 regulations. The 1N5256B TR PBFREE meets environmental and regulatory requirements for lead-free component manufacturing and is suitable for applications with RoHS compliance mandates.

Q: How do the reverse leakage current specifications compare?

A: The 1N5545 specifies 10 nA @ 24 V reverse leakage, while the 1N5256B TR PBFREE specifies 100 nA @ 23 V. The 1N5545 exhibits lower reverse leakage current. Applications sensitive to leakage current characteristics should evaluate this parameter against specific circuit requirements.

Q: Is the extended temperature range of the 1N5256B TR PBFREE (-65°C to 200°C) necessary for standard applications?

A: The extended upper temperature limit of 200°C (versus 175°C for the 1N5545) provides operational margin for high-temperature environments. Standard applications operating within -65°C to 175°C range function identically with either component. Selection depends on whether the application environment requires the additional 25°C upper temperature margin.