3KP33 Transient Voltage Suppressor - Equivalent & Substitute Parts

Part Overview

The 3KP33 is a unidirectional Zener transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection applications. This component features a 33V reverse standoff voltage rating with a 55.97V maximum clamping voltage and 56.3A peak pulse current capability in a through-hole P600 axial package. The 3KP33 is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for new designs and ongoing production requirements.

Substiute Parts

3KP33

Littelfuse Inc.In Stock: 10523KP33 Datasheet

Current PartRFQ

5KP33A

Diotec SemiconductorIn Stock: 43285KP33A Datasheet

DirectRFQ

5KP33A-TP

Micro Commercial CoIn Stock: 12205KP33A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 3KP33 are qualified based on the following electrical and mechanical parameters:

• Voltage - Reverse Standoff (Typ): 33V (exact match required)
• Voltage - Clamping (Max) @ Ipp: Must not exceed 55.97V to ensure equivalent protection performance
• Current - Peak Pulse (10/1000µs): Must meet or exceed 56.3A minimum requirement
• Power - Peak Pulse: Must meet or exceed 3000W minimum rating
• Mounting Type: Through Hole (required for form-fit compatibility)
• Package / Case: P600 or R-6 axial packages (mechanically compatible with P600 footprint)
• Type: Zener unidirectional TVS diode
• Unidirectional Channels: 1 (single channel configuration)

The identified substitutes maintain these critical parameters while offering active product status and improved availability compared to the obsolete 3KP33.

Parameter Comparison

Engineering Selection Recommendations

Both 5KP33A and 5KP33A-TP qualify as functional equivalents to the 3KP33 based on electrical parameter compatibility and through-hole axial package configuration.

The 5KP33A (Diotec Semiconductor) maintains the P600 package specification identical to the original 3KP33, providing direct mechanical compatibility without PCB layout modifications. This part is HTSUS classified and carries active product status with 4300 units in stock.

The 5KP33A-TP (Micro Commercial Co) offers ROHS3 compliance and REACH Unaffected status, with operating temperature range matching the original specification (-55°C to 175°C). The R-6 axial package is mechanically compatible with P600 footprints in standard through-hole applications. This part carries active product status with 1180 units in stock.

Both substitutes exceed the original 3000W power rating (5000W capability), providing enhanced margin for transient protection. The 5KP33A additionally specifies 94A peak pulse current, exceeding the 56.3A requirement of the 3KP33.

Frequently Asked Questions (FAQ)

Q: Can the 5KP33A and 5KP33A-TP be used interchangeably with the 3KP33?

A: Both parts meet the electrical requirements for 3KP33 substitution. The 5KP33A maintains identical P600 package specification. The 5KP33A-TP uses an R-6 axial package, which is mechanically compatible with standard P600 through-hole footprints. Selection depends on specific PCB layout requirements and compliance certifications needed for your application.

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

A: Both are axial through-hole packages for TVS diodes. The P600 and R-6 designations refer to different physical dimensions and lead configurations. Both are compatible with standard through-hole PCB layouts designed for axial components. Verify specific lead spacing and hole diameter requirements for your PCB design.

Q: Why do the substitute parts have higher power ratings than the 3KP33?

A: The 5KP33A and 5KP33A-TP are rated for 5000W peak pulse power compared to the 3KP33's 3000W rating. This higher rating provides additional safety margin and does not affect compatibility. The parts will function identically at the 3000W operating point of the original design.

Q: Are there compliance or certification differences between the substitutes?

A: The 5KP33A-TP carries ROHS3 compliance and REACH Unaffected status. The 5KP33A does not specify ROHS status. Both parts carry EAR99 ECCN classification and HTSUS 8541.10.0080 coding. Verify compliance requirements for your specific application and region.

Q: What is the minimum operating temperature difference between substitutes?

A: The 5KP33A operates from -50°C to 175°C, while the 3KP33 and 5KP33A-TP both operate from -55°C to 175°C. If your application requires operation below -50°C, the 5KP33A-TP is the appropriate selection.