ZPY91-TAP Zener Diode Equivalent & Substitute Parts

Part Overview

The ZPY91-TAP is a 91 V, 1.3 W Zener diode manufactured by Vishay General Semiconductor - Diodes Division in DO-204AL (DO-41) axial through-hole packaging. This component is classified as obsolete, indicating discontinuation from the manufacturer. Identification of equivalent substitute parts is necessary to maintain design continuity and ensure component availability for production, repair, and maintenance applications. Substitute parts must maintain functional compatibility within the electrical and mechanical constraints of the original design.

Substiute Parts

ZPY91-TAP

Vishay General Semiconductor - Diodes DivisionIn Stock: 1000ZPY91-TAP Datasheet

Current PartRFQ

1N5951AG

Microsemi CorporationIn Stock: 8011N5951AG Datasheet

MFR RecommendedRFQ

1N5951CG

Microsemi CorporationIn Stock: 8581N5951CG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ZPY91-TAP is determined by the following critical parameters:

Mechanical Compatibility: Package type (DO-204AL/DO-41 axial through-hole) and mounting configuration must remain identical to ensure physical fit and solderability.

Electrical Compatibility: Zener voltage rating, power dissipation capability, impedance characteristics, and reverse leakage current define functional equivalence. Substitute parts must operate within the voltage and power specifications of the original circuit design.

Tolerance and Precision: Voltage tolerance affects circuit regulation accuracy and must be evaluated against application requirements.

Thermal Performance: Maximum operating temperature and power rating determine thermal stability under load conditions.

Compliance and Status: Product status (active vs. obsolete) and regulatory compliance (RoHS, REACH, AEC-Q101) influence long-term availability and application suitability.

The substitute parts identified (1N5951AG and 1N5951CG) share identical mechanical packaging and mounting type with the ZPY91-TAP. However, electrical parameters differ and must be evaluated for circuit compatibility.

Parameter Comparison

Engineering Selection Recommendations

Mechanical Fit: Both 1N5951AG and 1N5951CG are compatible with the ZPY91-TAP in terms of package type (DO-204AL/DO-41 axial through-hole) and mounting configuration. Direct physical substitution is possible without PCB modification.

Electrical Differences: The substitute parts operate at 120 V nominal Zener voltage, compared to the original 91 V rating. This 29 V difference represents a significant electrical deviation. Circuit designers must verify that 120 V regulation is acceptable for the intended application. The lower power rating (1.25 W vs. 1.3 W) and higher impedance (380 Ohms vs. 120 Ohms) also differ from the original specification.

Tolerance Considerations: The 1N5951CG offers ±2% tolerance, superior to the original ±5% tolerance, providing tighter voltage regulation. The 1N5951AG provides ±10% tolerance, which is less precise than the original part.

Product Status and Compliance: Both substitute parts are active products with current manufacturing availability. However, both are RoHS non-compliant, whereas the ZPY91-TAP is ROHS3 compliant. The original part carries automotive-grade qualification (AEC-Q101), which is not specified for the substitute parts. Applications requiring automotive compliance or RoHS certification must evaluate these differences against regulatory requirements.

Temperature Range: The substitute parts offer an extended operating temperature range (-65°C to 175°C) compared to the original specification (175°C maximum), providing improved low-temperature performance.

Substitution is mechanically feasible but requires electrical circuit validation due to voltage rating differences and compliance status changes.

Frequently Asked Questions (FAQ)

Q: Can 1N5951AG and 1N5951CG be used as direct replacements for ZPY91-TAP?

A: Mechanical substitution is possible due to identical DO-204AL/DO-41 axial through-hole packaging. However, electrical substitution requires circuit validation. The 120 V Zener voltage of the substitute parts differs significantly from the original 91 V rating and must be evaluated against circuit design specifications.

Q: What are the key electrical differences between ZPY91-TAP and the substitute parts?

A: The primary differences are: Zener voltage (91 V vs. 120 V), power rating (1.3 W vs. 1.25 W), impedance (120 Ohms vs. 380 Ohms), and reverse leakage current (500 nA @ 68 V vs. 1 µA @ 91.2 V). These parameters affect voltage regulation, power dissipation, and circuit performance.

Q: Which substitute part offers better voltage tolerance?

A: The 1N5951CG provides ±2% tolerance, superior to both the original ZPY91-TAP (±5%) and the 1N5951AG (±10%). Tighter tolerance improves voltage regulation accuracy in precision applications.

Q: Are the substitute parts suitable for automotive applications?

A: The ZPY91-TAP carries automotive-grade qualification (AEC-Q101). The substitute parts do not specify automotive qualification. Applications requiring automotive compliance must verify qualification status with the manufacturer before substitution.

Q: What is the impact of RoHS compliance differences?

A: The ZPY91-TAP is ROHS3 compliant, while both substitute parts are RoHS non-compliant. Applications subject to RoHS regulations must account for this compliance difference in design and procurement decisions.

Q: Do the substitute parts fit the same PCB footprint?

A: Yes. Both 1N5951AG and 1N5951CG use identical DO-204AL/DO-41 axial through-hole packaging, ensuring mechanical compatibility with existing PCB designs without layout modification.

Q: What is the significance of the higher impedance in substitute parts?

A: The substitute parts have impedance of 380 Ohms compared to 120 Ohms in the original. Higher impedance affects dynamic response and voltage regulation characteristics under load transients. Circuit performance must be validated for the specific application.