Equivalent & Substitute Parts for 3KP45A-B TVS Diode

Part Overview

The 3KP45A-B is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose voltage clamping applications. This component features a 45V reverse standoff voltage with a 72.7V maximum clamping voltage and 41.3A peak pulse current capability in a through-hole P600 axial package. The part is currently classified as obsolete, making equivalent substitutes necessary for ongoing design support and procurement.

Substiute Parts

3KP45A-B

Littelfuse Inc.In Stock: 8243KP45A-B Datasheet

Current PartRFQ

5KP45A-B

Littelfuse Inc.In Stock: 9865KP45A-B Datasheet

DirectRFQ

3KP45A-TP

Micro Commercial CoIn Stock: 11223KP45A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 3KP45A-B is determined by matching the following critical electrical and mechanical parameters:

• Voltage - Reverse Standoff: 45V (±tolerance)
• Voltage - Clamping (Max) @ Ipp: 72.7V
• Current - Peak Pulse (10/1000µs): 41.3A minimum
• Power - Peak Pulse: 3000W minimum
• Operating Temperature Range: -55°C to 175°C
• Mounting Type: Through Hole
• Package Configuration: Axial (P600 or equivalent footprint)
• Type: Unidirectional Zener TVS Diode

Two substitute parts meet these criteria:

1. 5KP45A-B (Littelfuse Inc.) - Direct electrical equivalent with higher current rating (70.2A) and increased power dissipation (5000W), maintaining identical voltage specifications and package footprint.

2. 3KP45A-TP (Micro Commercial Co) - Electrical equivalent with identical current (41.3A) and power (3000W) ratings, featuring an alternative axial package (R-6) with compatible through-hole mounting.

Parameter Comparison

Engineering Selection Recommendations

5KP45A-B is the preferred direct substitute when higher transient energy absorption is required or when design margins for peak pulse current and power dissipation are desired. This part maintains identical voltage specifications and P600 package footprint, enabling direct board-level replacement. Active product status ensures long-term availability and supply chain stability.

3KP45A-TP provides an equivalent electrical solution with matched current and power ratings to the original 3KP45A-B. The R-6 axial package requires verification of PCB footprint compatibility, as lead spacing may differ from the P600 package. This option is suitable for designs where the original specifications are sufficient and package dimensions are accommodated.

Both substitutes carry ROHS3 compliance and are manufactured by established component suppliers with active product status, ensuring regulatory compliance and procurement reliability.

Frequently Asked Questions (FAQ)

Q: Can 5KP45A-B be used as a direct replacement for 3KP45A-B?

A: Yes. The 5KP45A-B maintains identical voltage specifications (45V standoff, 72.7V clamping) and uses the same P600 axial package. The higher current rating (70.2A vs. 41.3A) and power dissipation (5000W vs. 3000W) provide additional margin without affecting circuit compatibility.

Q: What is the difference between the P600 and R-6 packages?

A: Both are through-hole axial packages for TVS diodes. P600 and R-6 differ in lead diameter and spacing. PCB footprint compatibility must be verified before selecting 3KP45A-TP as a substitute.

Q: Are all three parts RoHS compliant?

A: Yes. The 3KP45A-B, 5KP45A-B, and 3KP45A-TP are all ROHS3 compliant.

Q: Why is 3KP45A-B marked as obsolete?

A: Obsolete status indicates the part is no longer manufactured by Littelfuse Inc. Active substitutes (5KP45A-B and 3KP45A-TP) are available for new designs and ongoing production support.

Q: Can these parts be used interchangeably in all applications?

A: Electrical interchangeability is confirmed for voltage and temperature specifications. Package footprint compatibility must be verified for each application. The 5KP45A-B offers superior transient protection due to higher current and power ratings.