1SMB40AT3 Equivalent & Substitute Parts

Part Overview

The 1SMB40AT3 is a transient voltage suppressor (TVS) diode manufactured by onsemi, designed for general-purpose overvoltage protection in surface mount applications. This part operates at a 40V reverse standoff voltage with a 64.5V clamping voltage and is classified as obsolete. Due to its obsolete status, equivalent substitute parts from active manufacturers are necessary to maintain design continuity and ensure long-term component availability for new production and field replacements.

Substiute Parts

1SMB40AT3

onsemiIn Stock: 51631SMB40AT3 Datasheet

Current PartRFQ

SMBJ40A

MDDIn Stock: 17458SMBJ40A Datasheet

DirectRFQ

SMBJ40A-TR

STMicroelectronicsIn Stock: 3286SMBJ40A-TR Datasheet

DirectRFQ

PTVS40VP1UP,115

Nexperia USA Inc.In Stock: 5873PTVS40VP1UP,115 Datasheet

SimilarRFQ

SMBJ40A-13-F

Diodes IncorporatedIn Stock: 189781SMBJ40A-13-F Datasheet

SimilarRFQ

SMBJ40A-TP

Micro Commercial CoIn Stock: 8503SMBJ40A-TP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 1SMB40AT3 is determined by the following electrical and mechanical parameters:

• Voltage - Reverse Standoff (Typ): 40V
• Voltage - Clamping (Max) @ Ipp: 64.5V
• Current - Peak Pulse (10/1000µs): 9.3A to 9.7A
• Power - Peak Pulse: 600W
• Mounting Type: Surface Mount
• Package / Case: DO-214AA (SMB) or SOD-128
• Unidirectional Channels: 1
• RoHS Status: ROHS3 Compliant (all substitutes)
• MSL: 1 (Unlimited)

All substitute parts maintain identical voltage specifications and peak pulse power ratings. Substitutes are available in two package configurations: SMB/DO-214AA (direct mechanical equivalent) and SOD-128 (alternative package for space-constrained applications). All active substitutes comply with ROHS3, addressing the non-compliance status of the obsolete original part.

Parameter Comparison

Engineering Selection Recommendations

For Direct Mechanical Replacement (SMB/DO-214AA Package):

SMBJ40A-13-F (Diodes Incorporated) is the preferred substitute. This part maintains identical electrical specifications, operates across the full temperature range (-55°C to 150°C), and offers the highest inventory availability (189,737 pcs). ROHS3 compliance resolves the regulatory non-compliance of the original part.

SMBJ40A-TP (Micro Commercial Co) provides an alternative with extended upper operating temperature to 175°C, suitable for high-temperature applications. SMBJ40A-TR (STMicroelectronics) offers TRANSIL™ series qualification with slightly higher peak pulse current (9.7A) and is available in cut tape packaging.

For Alternative Package (SOD-128):

PTVS40VP1UP,115 (Nexperia USA Inc.) is the only substitute available in SOD-128 package. This part includes AEC-Q101 automotive qualification and is suitable for space-constrained designs requiring smaller form factors while maintaining identical electrical performance.

For General-Purpose Applications:

SMBJ40A (MDD) provides a cost-effective option with standard temperature range and active product status. All SMB-packaged substitutes are mechanically and electrically interchangeable with the original 1SMB40AT3.

Frequently Asked Questions (FAQ)

Q: Can I use PTVS40VP1UP,115 as a direct replacement for 1SMB40AT3?

A: PTVS40VP1UP,115 is electrically equivalent but uses SOD-128 package instead of SMB/DO-214AA. It is suitable only if your PCB layout accommodates the smaller SOD-128 footprint. For direct board-level replacement without layout changes, use SMB-packaged alternatives.

Q: What is the difference between the SMB-packaged substitutes?

A: All SMB-packaged substitutes (SMBJ40A, SMBJ40A-TR, SMBJ40A-13-F, SMBJ40A-TP) share identical electrical specifications and mechanical compatibility. Differences include manufacturer, operating temperature range, and packaging format (cut tape vs. tape & reel). Selection depends on supply chain preference and temperature requirements.

Q: Why is ROHS3 compliance important for this substitution?

A: The original 1SMB40AT3 is RoHS non-compliant. All active substitutes are ROHS3 compliant, meeting current regulatory requirements for new production and ensuring long-term market availability.

Q: Does the 9.7A peak pulse current of SMBJ40A-TR affect compatibility?

A: No. The 9.7A specification is within the acceptable range for this voltage class and represents improved performance. The part remains fully compatible with designs specified for 9.3A.

Q: Which substitute has the best availability?

A: SMBJ40A-13-F (Diodes Incorporated) has the highest inventory at 189,737 pcs, followed by SMBJ40A-TP (8,442 pcs) and PTVS40VP1UP,115 (5,780 pcs).

Q: Can I mix different manufacturers' substitutes in the same design?

A: Yes. All substitutes meet identical electrical and mechanical specifications. However, for consistency in procurement and quality control, using a single manufacturer per production batch is recommended.