3KP43A Equivalent & Substitute Parts

Part Overview

The 3KP43A is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse, designed for general-purpose overvoltage protection applications. This component features a 43V reverse standoff voltage with a 69.4V maximum clamping voltage and 3000W peak pulse power rating. The part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for continued system support and new designs.

Substiute Parts

3KP43A

LittelfuseIn Stock: 12153KP43A Datasheet

Current PartRFQ

5KP43A

Littelfuse Inc.In Stock: 34105KP43A Datasheet

DirectRFQ

3KP43A-TP

Micro Commercial CoIn Stock: 12493KP43A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3KP43A is determined by the following critical parameters:

• Voltage Rating Match: Reverse standoff voltage of 43V, breakdown voltage minimum of 47.8V, and clamping voltage maximum of 69.4V must be maintained
• Package Compatibility: Through-hole axial package (P600 or equivalent R-6) required for direct board-level replacement
• Thermal Range: Operating temperature range of -55°C to 175°C (TJ) must be supported
• Unidirectional Configuration: Single-channel zener TVS diode topology
• Compliance: RoHS3 compliance and MSL Level 1 required

The 5KP43A and 3KP43A-TP meet these criteria with identical voltage specifications and compatible through-hole packages, though with differing power ratings and peak pulse current capabilities.

Parameter Comparison

Engineering Selection Recommendations

5KP43A (Littelfuse Inc.): This part is the primary active substitute, manufactured by the original equipment supplier. It maintains identical voltage specifications and through-hole P600 package compatibility. The 5KP43A provides enhanced performance with 5000W peak pulse power and 74.6A peak pulse current, exceeding the original 3KP43A specifications. This part is recommended for applications where higher transient energy absorption is beneficial or where the original 3000W rating is marginal. Active product status ensures long-term availability and supply chain continuity.

3KP43A-TP (Micro Commercial Co): This alternative maintains electrical equivalence with matching 43V standoff voltage, 69.4V clamping voltage, and 3000W power rating. The R-6 axial package provides mechanical compatibility with through-hole mounting. This option is suitable for cost-sensitive applications or where secondary-source qualification is acceptable. Active product status supports ongoing procurement.

Both substitutes maintain full compliance with RoHS3 requirements and MSL Level 1 moisture sensitivity specifications, ensuring compatibility with standard manufacturing and storage protocols.

Frequently Asked Questions (FAQ)

Q: Can the 5KP43A directly replace the 3KP43A in existing designs?

A: Yes. The 5KP43A maintains identical voltage specifications (43V standoff, 69.4V clamping) and through-hole axial package compatibility. The increased power rating (5000W vs. 3000W) and peak pulse current (74.6A vs. 43.2A) represent performance enhancements that do not compromise backward compatibility.

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

A: Both are through-hole axial packages for TVS diodes. P600 and R-6 are equivalent mechanical form factors used by different manufacturers. The 3KP43A-TP uses the R-6 designation while the original and 5KP43A use P600. Both support identical through-hole board mounting.

Q: Why is the 3KP43A obsolete?

A: The 3KP43A has been discontinued by Littelfuse. The 5KP43A serves as the active replacement in the manufacturer's product line, offering improved specifications while maintaining voltage compatibility.

Q: Are there any thermal or compliance differences between substitutes?

A: No. All three parts operate across the identical temperature range (-55°C to 175°C TJ) and maintain ROHS3 compliance with MSL Level 1 ratings. Thermal and environmental performance are equivalent.

Q: Which substitute should be selected for new designs?

A: The 5KP43A is recommended for new designs due to active product status, manufacturer support, and enhanced power handling. The 3KP43A-TP is suitable where secondary-source qualification or cost optimization is a design requirement.