SMF43A Transient Voltage Suppressor - Equivalent & Substitute Parts

Part Overview

The SMF43A is an active Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection in surface-mount applications. This unidirectional Zener diode operates with a 43V reverse standoff voltage and provides 200W peak pulse power dissipation in a compact SOD-123F package. The part is actively produced and ROHS3 compliant, making it suitable for modern electronic circuit protection requirements. Substitute parts are identified to provide alternative sourcing options while maintaining equivalent electrical and mechanical performance.

Substiute Parts

SMF43A

Littelfuse Inc.In Stock: 17188SMF43A Datasheet

Current PartRFQ

SMF43A-TP

Micro Commercial CoIn Stock: 6234SMF43A-TP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMF43A are qualified based on strict equivalence across the following critical parameters:

• Voltage - Reverse Standoff: 43V (identical)
• Voltage - Breakdown (Min): 47.8V (identical)
• Voltage - Clamping (Max) @ Ipp: 69.4V (identical)
• Current - Peak Pulse (10/1000µs): 2.9A (identical)
• Power - Peak Pulse: 200W (identical)
• Package / Case: SOD-123F (identical)
• Mounting Type: Surface Mount (identical)
• Unidirectional Channels: 1 (identical)
• Type: Zener (identical)

The SMF43A-TP manufactured by Micro Commercial Co meets all electrical and mechanical equivalence criteria and qualifies as a direct substitute. Both parts share the same base product number (SMF43) and deliver identical performance characteristics for transient voltage suppression applications.

Parameter Comparison

Engineering Selection Recommendations

Both the SMF43A and SMF43A-TP are active products with ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements for electronic component procurement. Selection between these parts should be based on availability, packaging preference (Tape & Reel versus Cut Tape & Digi-Reel), and supply chain considerations. The SMF43A-TP offers an extended operating temperature range (-65°C to 175°C) compared to the SMF43A (-55°C to 150°C), which may be advantageous for applications requiring broader thermal performance. Both parts are electrically and mechanically interchangeable for standard circuit protection applications.

Frequently Asked Questions (FAQ)

Q: Can SMF43A-TP be used as a direct replacement for SMF43A?

A: Yes. Both parts are electrically and mechanically equivalent, sharing identical voltage ratings (43V standoff, 47.8V breakdown, 69.4V clamping), current specifications (2.9A peak pulse), power dissipation (200W), and SOD-123F package geometry. They are functionally interchangeable in circuit applications.

Q: What is the difference between Tape & Reel and Cut Tape & Digi-Reel packaging?

A: Tape & Reel packaging is supplied on continuous carrier tape wound on reels, suitable for high-volume automated assembly. Cut Tape & Digi-Reel packaging provides smaller quantities cut from the tape and wound on alternative reel formats, typically for lower-volume or mixed-component orders. Both deliver identical components; packaging format is a supply and handling consideration.

Q: Are there operating temperature differences between these parts?

A: Yes. The SMF43A operates from -55°C to 150°C (junction temperature), while the SMF43A-TP operates from -65°C to 175°C (ambient temperature). For applications requiring extended thermal range, the SMF43A-TP provides broader temperature coverage.

Q: Do both parts meet current compliance standards?

A: Yes. Both SMF43A and SMF43A-TP are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic component use in regulated markets.

Q: What applications are these TVS diodes suitable for?

A: Both parts are rated for general-purpose transient voltage suppression applications. The 43V rating and 200W peak pulse power make them suitable for protecting circuits operating in the 43V nominal voltage range from transient overvoltage events.