SMP28-E3/85A Equivalent & Substitute Parts

Part Overview

The SMP28-E3/85A is a unidirectional Transient Voltage Suppressor (TVS) diode from Vishay General Semiconductor - Diodes Division, designed for general-purpose transient protection applications. This component features a 28V reverse standoff voltage with a 50V maximum clamping voltage and 8A peak pulse current capability in a surface-mount DO-220AA package. The part is currently classified as obsolete, necessitating identification of active equivalent alternatives to maintain design continuity and ensure supply chain availability for new production and field replacements.

Substiute Parts

SMP28-E3/85A

Vishay General Semiconductor - Diodes DivisionIn Stock: 962SMP28-E3/85A Datasheet

Current PartRFQ

SMP28-M3/85A

Vishay General Semiconductor - Diodes DivisionIn Stock: 957SMP28-M3/85A Datasheet

DirectRFQ

PTVS30VS1UR,115

Nexperia USA Inc.In Stock: 18886PTVS30VS1UR,115 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMP28-E3/85A are identified based on strict electrical and mechanical compatibility criteria. The primary substitution parameters are:

Critical Matching Parameters:

• Unidirectional channel configuration (1 channel required)
• Voltage - Reverse Standoff: 28V nominal (acceptable range: 28V to 30V)
• Voltage - Clamping (Max) @ Ipp: 50V maximum (acceptable range: 48.4V to 50V)
• Current - Peak Pulse (10/1000µs): 8A minimum (acceptable range: 8A to 8.3A)
• Power - Peak Pulse: 400W minimum
• Operating Temperature Range: -55°C to 150°C minimum
• RoHS3 Compliance: Required
• Mounting Type: Surface Mount

Identified Substitutes:

1. SMP28-M3/85A (Direct Manufacturer Equivalent) – Same manufacturer, identical electrical specifications, active product status, same package and series designation.

2. PTVS30VS1UR,115 (Manufacturer-Recommended Alternative) – Nexperia part with compatible electrical parameters within acceptable tolerance bands, automotive-grade qualification (AEC-Q101), different package format (SOD-123W), active product status.

Parameter Comparison

Engineering Selection Recommendations

SMP28-M3/85A is the primary recommended substitute. This part maintains identical electrical specifications and series designation (TransZorb®, eSMP®) as the obsolete SMP28-E3/85A while offering active product status and equivalent inventory availability. The DO-220AA package compatibility eliminates the need for PCB layout modifications. Both parts are ROHS3 compliant with MSL 1 rating.

PTVS30VS1UR,115 serves as an alternative substitute when SMP28-M3/85A availability is constrained. This Nexperia part operates within acceptable electrical parameter tolerances: the 30V reverse standoff voltage is 2V higher than the original specification, and the 48.4V clamping voltage is 1.6V lower, both within acceptable margins for general-purpose transient protection. The part carries AEC-Q101 automotive qualification, providing additional reliability assurance. However, the SOD-123W package requires PCB layout redesign compared to the original DO-220AA footprint. This substitution is suitable for applications where package redesign is feasible and automotive-grade qualification is beneficial or required.

Frequently Asked Questions (FAQ)

Q: Can SMP28-M3/85A be used as a direct drop-in replacement for SMP28-E3/85A?

A: Yes. SMP28-M3/85A is a direct equivalent with identical electrical specifications, same DO-220AA package, and equivalent series designation. No circuit or PCB modifications are required.

Q: What are the key differences between SMP28-E3/85A and PTVS30VS1UR,115?

A: The primary differences are: (1) Reverse standoff voltage is 30V versus 28V; (2) Clamping voltage is 48.4V versus 50V; (3) Peak pulse current is 8.3A versus 8A; (4) Package is SOD-123W versus DO-220AA; (5) Manufacturer is Nexperia versus Vishay; (6) PTVS30VS1UR,115 carries AEC-Q101 automotive qualification. All electrical parameters remain within acceptable tolerance bands for transient suppression applications.

Q: Does PTVS30VS1UR,115 require PCB layout changes?

A: Yes. The SOD-123W package has a different footprint than the DO-220AA package used in the original design. PCB layout redesign is necessary for this substitution.

Q: Are both substitute parts RoHS3 compliant?

A: Yes. Both SMP28-M3/85A and PTVS30VS1UR,115 are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating.

Q: Which substitute should be selected for automotive applications?

A: PTVS30VS1UR,115 is qualified to AEC-Q101 automotive standards. For non-automotive applications, SMP28-M3/85A is the preferred choice due to package compatibility and direct electrical equivalence.

Q: What is the operating temperature range for both substitutes?

A: Both substitutes support -55°C to 150°C operating temperature range, meeting the thermal requirements of the original SMP28-E3/85A.