SMF45A Equivalent & Substitute Parts

Part Overview

The SMF45A is a unidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection applications. This surface-mount component operates with a 45V reverse standoff voltage and provides 200W peak pulse power dissipation in a compact SOD-123F package. The part maintains active product status with full RoHS3 compliance and unlimited moisture sensitivity rating. Equivalent and substitute parts are identified to support procurement flexibility, inventory management, and supply chain continuity for applications requiring identical electrical and mechanical specifications.

Substiute Parts

SMF45A

Littelfuse Inc.In Stock: 20321SMF45A Datasheet

Current PartRFQ

SMF45A-TP

Micro Commercial CoIn Stock: 3566SMF45A-TP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SMF45A are qualified based on strict electrical and mechanical parameter matching. The following criteria determine substitution eligibility:

Critical Matching Parameters:

• Voltage - Reverse Standoff (Typ): 45V
• Voltage - Breakdown (Min): 50V
• Voltage - Clamping (Max) @ Ipp: 72.7V
• Current - Peak Pulse (10/1000µs): 2.8A
• Power - Peak Pulse: 200W
• Package / Case: SOD-123F
• Unidirectional Channels: 1
• Type: Zener

Compliance Parameters:

• RoHS3 Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)

The SMF45A-TP manufactured by Micro Commercial Co meets all critical electrical specifications and compliance requirements, qualifying it as a direct substitute for the Littelfuse SMF45A in applications requiring identical voltage suppression and current handling characteristics.

Parameter Comparison

Engineering Selection Recommendations

Both the SMF45A and SMF45A-TP are active products with full RoHS3 compliance and REACH unaffected status, meeting current regulatory requirements for electronic component procurement. Selection between these parts may be based on inventory availability, supplier lead times, or established vendor relationships, as electrical performance and mechanical compatibility are identical. The SMF45A-TP offers an extended operating temperature range (-65°C ~ 175°C TA) compared to the SMF45A (-55°C ~ 150°C TJ), providing additional thermal margin for applications operating at elevated ambient temperatures. Both components are suitable for general-purpose transient voltage suppression in surface-mount circuit designs requiring SOD-123F package compatibility.

Frequently Asked Questions (FAQ)

Q: Can SMF45A-TP be used as a direct replacement for SMF45A in existing designs?

A: Yes. Both parts share identical electrical specifications including 45V reverse standoff voltage, 72.7V clamping voltage, 2.8A peak pulse current, and 200W peak pulse power. The SOD-123F package dimensions and pinout are identical, enabling direct PCB substitution without design modification.

Q: What are the key differences between SMF45A and SMF45A-TP?

A: The primary differences are manufacturer (Littelfuse vs. Micro Commercial Co) and operating temperature range. The SMF45A-TP supports -65°C to 175°C (TA) versus SMF45A's -55°C to 150°C (TJ). All electrical protection characteristics remain identical.

Q: Are both parts RoHS compliant?

A: Yes. Both SMF45A and SMF45A-TP are ROHS3 compliant with unlimited moisture sensitivity rating (MSL 1), meeting current environmental and reliability standards.

Q: Does package compatibility affect substitution?

A: No. Both parts use the SOD-123F surface-mount package with identical footprint and pinout, ensuring mechanical and electrical compatibility on PCBs designed for either component.

Q: Which part should be selected for high-temperature applications?

A: For applications requiring operation above 150°C ambient temperature, the SMF45A-TP with its extended -65°C to 175°C operating range provides additional thermal margin. For standard temperature ranges, either part is suitable.