SMP18A-E3/85A Equivalent & Substitute Parts

Part Overview

The SMP18A-E3/85A is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Vishay General Semiconductor - Diodes Division. This component is designed for general-purpose transient voltage suppression applications, featuring an 18V reverse standoff voltage and 29.2V maximum clamping voltage. The part is currently classified as obsolete, making identification of equivalent and substitute components essential for ongoing design support and procurement.

Substiute Parts

SMP18A-E3/85A

Vishay General Semiconductor - Diodes DivisionIn Stock: 950SMP18A-E3/85A Datasheet

Current PartRFQ

SMP18A-M3/85A

Vishay General Semiconductor - Diodes DivisionIn Stock: 12482SMP18A-M3/85A Datasheet

DirectRFQ

PTVS18VS1UR,115

Nexperia USA Inc.In Stock: 18836PTVS18VS1UR,115 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMP18A-E3/85A are identified based on electrical parameter equivalence and mechanical compatibility. The critical parameters determining substitution eligibility are:

• Voltage - Reverse Standoff: 18V (Typ)
• Voltage - Clamping (Max) @ Ipp: 29.2V
• Current - Peak Pulse (10/1000µs): 13.7A
• Power - Peak Pulse: 400W
• Operating Temperature Range: -55°C ~ 150°C
• RoHS3 Compliance

Two substitute parts meet these electrical specifications. The first substitute maintains identical packaging (DO-220AA), while the second substitute achieves electrical equivalence with a different surface-mount package (SOD-123W).

Parameter Comparison

Engineering Selection Recommendations

SMP18A-M3/85A is the primary substitute for SMP18A-E3/85A. Both parts are manufactured by Vishay General Semiconductor - Diodes Division and share identical electrical specifications and packaging. The SMP18A-M3/85A carries active product status with significantly higher inventory availability (12,400 pcs vs. 925 pcs), making it the preferred choice for direct replacement in existing designs.

PTVS18VS1UR,115 is an alternate substitute manufactured by Nexperia USA Inc. This part maintains all critical electrical parameters but uses SOD-123W packaging instead of DO-220AA. This substitute is suitable only for applications where PCB layout and footprint can accommodate the different package geometry. The PTVS18VS1UR,115 carries AEC-Q101 automotive qualification, providing additional compliance for automotive applications.

Frequently Asked Questions (FAQ)

Q: Can SMP18A-M3/85A be used as a direct replacement for SMP18A-E3/85A?

A: Yes. Both parts are manufactured by Vishay and share identical electrical specifications, voltage ratings, current ratings, power dissipation, operating temperature range, and packaging. The SMP18A-M3/85A is the direct equivalent with active product status.

Q: What is the key difference between SMP18A-M3/85A and PTVS18VS1UR,115?

A: The electrical specifications are identical. The primary difference is packaging: SMP18A-M3/85A uses DO-220AA while PTVS18VS1UR,115 uses SOD-123W. Package selection depends on PCB layout requirements and available footprint space.

Q: Is PTVS18VS1UR,115 suitable for automotive applications?

A: Yes. PTVS18VS1UR,115 carries AEC-Q101 automotive qualification. However, the package change from DO-220AA to SOD-123W must be accommodated in the PCB design.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. SMP18A-M3/85A and PTVS18VS1UR,115 are both ROHS3 compliant with MSL rating of 1 (Unlimited).

Q: What is the operating temperature specification difference between the main part and substitutes?

A: SMP18A-E3/85A and SMP18A-M3/85A specify operating temperature as TJ (junction temperature) -55°C ~ 150°C. PTVS18VS1UR,115 specifies TA (ambient temperature) -55°C ~ 150°C. Both ranges are equivalent for practical application purposes.