3KP33CA-B Equivalent & Substitute Parts

Part Overview

The 3KP33CA-B is a Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient voltage protection applications. This bidirectional zener diode features a 33V reverse standoff voltage with a 53.3V maximum clamping voltage and 56.3A peak pulse current capability in a through-hole P600 axial package. The part is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and procurement.

Substiute Parts

3KP33CA-B

Littelfuse Inc.In Stock: 10073KP33CA-B Datasheet

Current PartRFQ

5KP33CA-B

Littelfuse Inc.In Stock: 14615KP33CA-B Datasheet

DirectRFQ

3KP33CA-TP

Micro Commercial CoIn Stock: 9853KP33CA-TP Datasheet

MFR RecommendedRFQ

5KP33CA-TP

Micro Commercial CoIn Stock: 168145KP33CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 3KP33CA-B are identified based on the following critical parameters that determine functional equivalence:

• Voltage - Reverse Standoff: 33V (exact match required)
• Voltage - Clamping (Max) @ Ipp: 53.3V (exact match required)
• Operating Temperature Range: -55°C to 175°C (exact match required)
• Mounting Type: Through Hole (exact match required)
• Type: Zener, Bidirectional (exact match required)

Substitutes are grouped into two categories:

Category 1: Direct Electrical Equivalents (Same Power Rating) Parts maintaining identical electrical specifications and 3000W peak pulse power rating with compatible packaging.

Category 2: Enhanced Performance Alternatives (Higher Power Rating) Parts with identical voltage specifications but increased peak pulse current and 5000W power rating, suitable for applications requiring higher transient energy absorption.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications): The 3KP33CA-TP (Micro Commercial Co) provides electrical equivalence with identical 33V standoff voltage, 53.3V clamping voltage, 56.3A peak pulse current, and 3000W power rating. This part is currently active and REACH compliant. Package compatibility requires verification: the 3KP33CA-TP uses R-6 axial packaging versus the original P600 package. Physical dimensions and lead spacing must be confirmed for PCB layout compatibility.

For Enhanced Performance (Higher Power Capability): The 5KP33CA-B (Littelfuse Inc.) maintains identical voltage specifications while providing increased transient energy absorption with 95.7A peak pulse current and 5000W power rating. This part is active, ROHS3 compliant, and uses the same P600 axial package as the original, ensuring direct mechanical compatibility. The 5KP33CA-TP (Micro Commercial Co) offers equivalent enhanced performance with 5000W rating in R-6 axial packaging.

Selection between direct equivalents and enhanced alternatives depends on application transient energy requirements and available PCB space for package variations.

Frequently Asked Questions (FAQ)

Q: Can the 5KP33CA-B replace the 3KP33CA-B in all applications? A: The 5KP33CA-B maintains identical voltage specifications (33V standoff, 53.3V clamping) and operating temperature range, making it electrically compatible. The increased peak pulse current (95.7A versus 56.3A) and power rating (5000W versus 3000W) provide enhanced transient protection capability. Package compatibility is maintained as both use P600 axial configuration. Applications with higher transient energy exposure benefit from this upgrade.

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 represent different physical form factors with potentially different lead spacing and body dimensions. Direct substitution between these packages requires PCB layout verification to confirm lead hole alignment and spacing compatibility.

Q: Are the Micro Commercial Co parts (3KP33CA-TP, 5KP33CA-TP) fully equivalent to Littelfuse parts? A: Both manufacturers' parts meet identical electrical specifications for voltage and temperature parameters. Micro Commercial Co parts are currently active with REACH compliance. Package differences (R-6 versus P600) require mechanical compatibility verification. Procurement and supply chain considerations may favor one manufacturer over another based on availability and lead times.

Q: Why is the 3KP33CA-B marked as obsolete? A: Obsolete status indicates the part is no longer manufactured by Littelfuse Inc. Active alternatives with identical electrical specifications are available from both Littelfuse (5KP series) and Micro Commercial Co, ensuring design continuity and supply chain support.

Q: Can I use the 5KP33CA-TP if peak pulse current data is not specified? A: The 5KP33CA-TP is rated for 5000W peak pulse power with the same 33V standoff and 53.3V clamping voltages as the original part. While specific peak pulse current is not provided in the datasheet parameters, the 5000W power rating indicates capability for higher transient energy absorption than the original 3000W specification.