SMF51AT1G Equivalent & Substitute Parts

Part Overview

The SMF51AT1G is a 51V Zener transient voltage suppressor (TVS) diode manufactured by onsemi in SOD-123FL surface mount packaging. This component is designed for general-purpose overvoltage protection applications with a peak pulse current rating of 2.4A and 200W peak pulse power dissipation. The part is currently listed as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement.

Substiute Parts

SMF51AT1G

onsemiIn Stock: 10474SMF51AT1G Datasheet

Current PartRFQ

SMF51A

MeritekIn Stock: 15621SMF51A Datasheet

DirectRFQ

SMF51A-E3-08

Vishay General Semiconductor - Diodes DivisionIn Stock: 17245SMF51A-E3-08 Datasheet

DirectRFQ

SMF51A-T13

Littelfuse Inc.In Stock: 823SMF51A-T13 Datasheet

DirectRFQ

SMF51A-TP

Micro Commercial CoIn Stock: 11674SMF51A-TP Datasheet

DirectRFQ

PTVS51VS1UR,115

Nexperia USA Inc.In Stock: 4244PTVS51VS1UR,115 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMF51AT1G are classified based on electrical and mechanical compatibility within the following criteria:

Direct Substitutes maintain identical or equivalent electrical performance across all critical parameters: 51V reverse standoff voltage, 56.7V minimum breakdown voltage, 82.4V maximum clamping voltage, and surface mount packaging. These parts are interchangeable in the same PCB footprint and circuit application.

Similar Substitutes meet the core voltage specifications (51V standoff, 56.7V breakdown, 82.4V clamping) but differ in peak pulse current rating, power dissipation, or package form factor. These parts require circuit-level verification for compatibility.

The key parameters determining substitution eligibility are:

• Voltage - Reverse Standoff: 51V
• Voltage - Breakdown (Min): 56.7V
• Voltage - Clamping (Max) @ Ipp: 82.4V
• Type: Zener, Unidirectional
• Mounting Type: Surface Mount

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Recommended Priority):

SMF51A-T13 (Littelfuse Inc.) and SMF51A-TP (Micro Commercial Co) are the primary direct substitutes. Both maintain identical electrical specifications (51V standoff, 56.7V breakdown, 82.4V clamping, 2.4A peak pulse current, 200W power) and SOD-123F packaging. Both parts are RoHS3 compliant and carry active product status. SMF51A-TP offers an extended operating temperature range (-65°C ~ 175°C) compared to the original specification, providing additional thermal margin for demanding applications.

SMF51A (Meritek) is functionally equivalent with marginally higher peak pulse current (2.43A vs. 2.4A) and maintains the same electrical performance envelope. This part is available in higher inventory quantities.

Alternative Substitute (Extended Performance):

SMF51A-E3-08 (Vishay General Semiconductor - Diodes Division) is packaged in DO-219AB (SMF) form factor rather than SOD-123F. This part offers extended operating temperature range (-65°C ~ 175°C) and includes capacitance specification (151pF @ 1MHz). PCB layout modification is required due to package change. This part carries eSMP® series designation and active product status with RoHS3 compliance.

Similar Substitute (Higher Current Rating):

PTVS51VS1UR,115 (Nexperia USA Inc.) maintains identical voltage specifications but provides doubled peak pulse current (4.9A) and power dissipation (400W). This part is packaged in SOD-123W and carries AEC-Q101 automotive qualification. Use this part only when higher transient current handling is required; it is not a direct footprint replacement due to package differences.

All substitute parts carry REACH Unaffected status and EAR99 ECCN classification matching the original part.

Frequently Asked Questions (FAQ)

Q: Can SMF51A-T13 be used as a direct replacement for SMF51AT1G?

A: Yes. SMF51A-T13 maintains identical electrical specifications (51V standoff, 56.7V breakdown, 82.4V clamping, 2.4A peak pulse current) and SOD-123F packaging. Both parts are RoHS3 compliant with MSL 1 rating. No circuit or layout modifications are required.

Q: What is the difference between SMF51A-TP and SMF51A-T13?

A: Both parts are electrically identical with matching voltage and current ratings. The primary difference is operating temperature range: SMF51A-TP operates from -65°C to 175°C, while SMF51A-T13 operates from -55°C to 150°C. SMF51A-TP provides wider thermal operating margin and is suitable for extended temperature applications.

Q: Why is PTVS51VS1UR,115 listed as a similar substitute rather than a direct substitute?

A: PTVS51VS1UR,115 differs in two critical aspects: package form factor (SOD-123W vs. SOD-123F) and peak pulse current rating (4.9A vs. 2.4A). While voltage specifications are identical, the different package requires PCB layout modification. Use this part only when higher transient current handling is required.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts (SMF51A, SMF51A-E3-08, SMF51A-T13, SMF51A-TP, and PTVS51VS1UR,115) carry RoHS3 compliance status. The original SMF51AT1G does not specify RoHS status.

Q: What is the MSL rating for these TVS diodes?

A: All parts carry MSL 1 (Unlimited) rating, indicating no moisture sensitivity restrictions for storage or handling.

Q: Can SMF51A-E3-08 be used in the same PCB footprint as SMF51AT1G?

A: No. SMF51A-E3-08 uses DO-219AB (SMF) packaging, which differs from the SOD-123F package of the original part. PCB layout and footprint modification is required. This part is suitable only when design changes can be accommodated.