SMF45AT1 Transient Voltage Suppressor - Equivalent & Substitute Parts

Part Overview

The SMF45AT1 is a unidirectional Zener-type transient voltage suppressor (TVS) diode designed for general-purpose overvoltage protection applications. Housed in a surface-mount SOD-123F package, this component provides 45V reverse standoff voltage with a 72.7V maximum clamping voltage and 2.8A peak pulse current capability.

The SMF45AT1 is classified as obsolete. Locating equivalent substitute parts is necessary to maintain design continuity and ensure component availability for new production builds and field replacements.

Substiute Parts

SMF45AT1

onsemiIn Stock: 1167SMF45AT1 Datasheet

Current PartRFQ

SMF45A-TP

Micro Commercial CoIn Stock: 3566SMF45A-TP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SMF45AT1 is determined by the following critical parameters:

• Voltage - Reverse Standoff: 45V (nominal)
• 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
• Mounting Type: Surface Mount
• Type: Zener, Unidirectional

Parts meeting these electrical and mechanical specifications are functionally equivalent and may be used as direct substitutes in the same circuit application.

Parameter Comparison

Engineering Selection Recommendations

The SMF45A-TP (Micro Commercial Co) is a direct functional equivalent to the SMF45AT1. Both parts share identical electrical specifications across all critical parameters: reverse standoff voltage, breakdown voltage, clamping voltage, peak pulse current, and power dissipation.

The SMF45A-TP offers the following advantages:

• Active product status ensures ongoing availability and supply chain continuity
• ROHS3 compliance meets current environmental and regulatory requirements
• Identical SOD-123F package and surface-mount configuration enable direct PCB substitution without layout modifications
• Expanded operating temperature range (-65°C ~ 175°C) provides additional thermal margin in some applications

The SMF45A-TP is supplied in Tape & Reel (TR) packaging, suitable for automated assembly processes.

Frequently Asked Questions (FAQ)

Q: Can the SMF45A-TP be used as a direct replacement for the SMF45AT1 on existing PCBs?

A: Yes. Both parts are housed in the SOD-123F surface-mount package with identical pinout and footprint. No PCB modifications are required.

Q: Are the electrical characteristics identical between these parts?

A: Yes. The SMF45A-TP and SMF45AT1 share identical specifications for reverse standoff voltage (45V), breakdown voltage (50V minimum), clamping voltage (72.7V maximum), peak pulse current (2.8A), and peak pulse power (200W).

Q: What is the difference in operating temperature range?

A: The SMF45AT1 operates from -55°C to 150°C (junction temperature). The SMF45A-TP operates from -65°C to 175°C (ambient temperature). The SMF45A-TP provides a wider temperature envelope.

Q: Does the packaging format affect compatibility?

A: The SMF45AT1 packaging format is not specified in the provided data. The SMF45A-TP is supplied in Tape & Reel (TR) format for automated assembly. Both parts use the same SOD-123FL supplier device package. Verify your assembly process requirements.

Q: Is RoHS compliance a factor in selecting a substitute?

A: The SMF45AT1 is RoHS non-compliant. The SMF45A-TP is ROHS3 compliant. If your application or market requires RoHS compliance, the SMF45A-TP is the appropriate choice.