1N5539B Zener Diode Equivalent & Substitute Parts

Part Overview

The 1N5539B is an active-status Zener diode manufactured by Microchip Technology, rated for 19 V nominal Zener voltage with 500 mW maximum power dissipation. This component is packaged in a DO-35 (DO-204AH) axial through-hole configuration and operates across a temperature range of -65°C to 175°C. The 1N5539B is utilized in voltage regulation and protection circuits where precise 19 V reference voltage is required. Equivalent substitute parts are identified when they maintain identical or compatible electrical specifications, mechanical packaging, and operational parameters within the defined tolerance ranges.

Substiute Parts

1N5539B

Microchip TechnologyIn Stock: 8151N5539B Datasheet

Current PartRFQ

1N5249BTR

Fairchild SemiconductorIn Stock: 1358041N5249BTR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1N5539B is determined by equivalence in the following critical parameters:

Primary Equivalence Criteria:

• Zener voltage (Vz): 19 V nominal
• Tolerance: ±5%
• Maximum power dissipation: 500 mW
• Package type: DO-35 (DO-204AH) axial through-hole
• Mounting configuration: Through-hole

Secondary Compatibility Parameters:

• Operating temperature range (minimum -65°C, maximum ≥175°C)
• Forward voltage (Vf) characteristics
• Reverse leakage current specifications
• Dynamic impedance (Zzt)

The 1N5249BTR from Fairchild Semiconductor meets all primary equivalence criteria and maintains compatibility across secondary parameters, with the exception of an extended maximum operating temperature (200°C versus 175°C) and improved dynamic impedance characteristics (23 Ohms versus 106 Ohms).

Parameter Comparison

Engineering Selection Recommendations

1N5249BTR Substitution Suitability:

The 1N5249BTR is a direct functional equivalent to the 1N5539B for 19 V Zener diode applications. Both components are active-status products with identical nominal Zener voltage, tolerance, and power ratings. The 1N5249BTR provides superior performance characteristics in two areas: lower dynamic impedance (23 Ohms versus 106 Ohms) and extended maximum operating temperature (200°C versus 175°C).

The 1N5249BTR exhibits higher reverse leakage current (100 nA @ 14 V versus 10 nA @ 17.1 V) and marginally higher forward voltage (1.2 V versus 1.1 V @ 200 mA). These differences remain within acceptable operational margins for standard voltage regulation and protection circuit applications.

Both components carry identical ECCN (EAR99) and HTSUS (8541.10.0050) classifications, confirming regulatory equivalence. The 1N5249BTR is available in significantly higher inventory (135,703 pieces versus 744 pieces), supporting supply chain continuity.

Frequently Asked Questions (FAQ)

Q: Can the 1N5249BTR replace the 1N5539B in existing circuit designs?

A: Yes. The 1N5249BTR maintains identical Zener voltage (19 V), tolerance (±5%), power rating (500 mW), and package configuration (DO-35 through-hole). Both components are functionally equivalent for voltage regulation and protection applications.

Q: What are the differences between these two parts?

A: The primary differences are: (1) Dynamic impedance: 1N5249BTR is 23 Ohms versus 1N5539B at 106 Ohms, providing lower output impedance; (2) Maximum operating temperature: 1N5249BTR extends to 200°C versus 1N5539B at 175°C; (3) Reverse leakage current: 1N5249BTR is 100 nA @ 14 V versus 1N5539B at 10 nA @ 17.1 V; (4) Forward voltage: 1N5249BTR is 1.2 V @ 200 mA versus 1N5539B at 1.1 V @ 200 mA.

Q: Are the packages physically identical?

A: Yes. Both the 1N5539B and 1N5249BTR use the DO-35 (DO-204AH) axial through-hole package. They are mechanically interchangeable without PCB layout modifications.

Q: Does the higher reverse leakage current of the 1N5249BTR affect circuit performance?

A: The reverse leakage difference (100 nA versus 10 nA) is negligible in standard voltage regulation and protection circuits. This parameter becomes relevant only in precision analog applications requiring extremely low bias currents, which are outside the typical application scope for 19 V Zener diodes.

Q: Which part should be selected for new designs?

A: Selection depends on application requirements. The 1N5249BTR is preferred for applications requiring extended temperature operation (above 175°C) or lower output impedance. The 1N5539B is suitable for standard applications within the -65°C to 175°C range. Both are active-status products with equivalent regulatory compliance.

Q: Are there any compliance or certification differences?

A: No. Both components share identical ECCN (EAR99) and HTSUS (8541.10.0050) classifications. Both are RoHS non-compliant and REACH Unaffected, indicating equivalent regulatory status.