SMF70A Transient Voltage Suppressor Equivalent & Substitute Parts

Part Overview

The SMF70A is an active Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose voltage transient protection in surface-mount applications. This unidirectional zener diode operates with a 70V reverse standoff voltage and provides 200W peak pulse power dissipation in a compact SOD-123F package. The part is RoHS3 compliant and carries unlimited moisture sensitivity rating (MSL 1), making it suitable for standard industrial and commercial environments. Alternative equivalent parts may be required due to inventory availability, regional supplier preferences, or specific application requirements within the allowed electrical and mechanical parameter ranges.

Substiute Parts

SMF70A

Littelfuse Inc.In Stock: 87333SMF70A Datasheet

Current PartRFQ

SMFE70A

Eaton - Electronics DivisionIn Stock: 9372SMFE70A Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SMF70A is permissible with the SMFE70A based on the following electrical and mechanical compatibility criteria:

Matching Parameters (Required for Substitution):

• Voltage - Reverse Standoff (Typ): 70V
• Voltage - Breakdown (Min): 77.8V
• Voltage - Clamping (Max) @ Ipp: 113V
• Power - Peak Pulse: 200W
• Package / Case: SOD-123F
• Mounting Type: Surface Mount
• Unidirectional Channels: 1

Allowable Variation:

• Current - Peak Pulse (10/1000µs): SMF70A specifies 1.5A; SMFE70A specifies 1.8A. The higher current rating in the substitute part remains within the same power dissipation envelope and does not compromise circuit protection.

Compliance Alignment:

• Both parts maintain RoHS compliance and unlimited moisture sensitivity rating (MSL 1), ensuring compatibility in standard manufacturing and storage environments.

Parameter Comparison

Engineering Selection Recommendations

Primary Selection (SMF70A): The SMF70A remains the preferred choice for applications requiring the full operating temperature range of -65°C to 150°C (TJ). This part is actively stocked with 87,290 units available and carries RoHS3 compliance certification.

Substitute Selection (SMFE70A): The SMFE70A is electrically and mechanically compatible for applications where the operating temperature range of -55°C to 150°C (TJ) is acceptable. This substitute part is manufactured by Eaton - Electronics Division and is actively stocked with 9,352 units available. The higher peak pulse current rating (1.8A versus 1.5A) provides additional margin within the same 200W power dissipation specification. Both parts maintain identical voltage characteristics and package specifications, ensuring direct circuit compatibility.

Compliance Considerations: Both parts are RoHS compliant and carry MSL 1 (unlimited) moisture sensitivity ratings, making them suitable for standard manufacturing and storage environments without special handling requirements.

Frequently Asked Questions (FAQ)

Q: Can SMFE70A be used as a direct replacement for SMF70A in all applications?

A: The SMFE70A is electrically and mechanically compatible with the SMF70A for applications operating within the temperature range of -55°C to 150°C (TJ). If your application requires operation below -55°C, the SMF70A is required. Both parts share identical voltage ratings, clamping characteristics, power dissipation, and package specifications.

Q: What is the significance of the different peak pulse current ratings (1.5A vs. 1.8A)?

A: Both parts are rated for 200W peak pulse power dissipation. The SMFE70A's higher current rating (1.8A) reflects a different internal design while maintaining the same power envelope. This does not affect substitutability; the higher rating provides additional design margin.

Q: Are there packaging differences between SMF70A and SMFE70A?

A: Both parts use the SOD-123F surface-mount package. The SMF70A is supplied in Cut Tape (CT) and Digi-Reel® packaging, while the SMFE70A is supplied in Tape & Reel (TR) packaging. The physical component dimensions and footprint are identical; packaging format differences relate only to supply and handling.

Q: Do both parts meet the same compliance standards?

A: Both parts are RoHS compliant and carry MSL 1 (unlimited) moisture sensitivity ratings. The SMF70A is specifically RoHS3 compliant, while the SMFE70A is RoHS compliant. Both meet REACH unaffected status and carry the same ECCN (EAR99) and HTSUS (8541.10.0080) classifications.

Q: Which part should I select for new designs?

A: For new designs, select based on your application's operating temperature requirements. If the full -65°C to 150°C range is needed, use SMF70A. If operation is limited to -55°C to 150°C, either part is acceptable. Both are active products with stable inventory availability.