Equivalent & Substitute Parts for 3KP33C-B TVS Diode

Part Overview

The 3KP33C-B is a 33V Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse, designed for general-purpose transient protection applications. This bidirectional Zener diode features a 55.97V maximum clamping voltage and 56.3A peak pulse current capability with 3kW peak pulse power rating. The part is classified as obsolete, necessitating identification of active equivalent and substitute components that maintain functional compatibility within the same voltage class and application category.

Substiute Parts

3KP33C-B

LittelfuseIn Stock: 11393KP33C-B Datasheet

Current PartRFQ

5KP33CA-B

Littelfuse Inc.In Stock: 14615KP33CA-B Datasheet

DirectRFQ

15KP33CA-TP

Micro Commercial CoIn Stock: 148915KP33CA-TP Datasheet

MFR RecommendedRFQ

15KPA33CAE3/TR13

Microchip TechnologyIn Stock: 95915KPA33CAE3/TR13 Datasheet

MFR RecommendedRFQ

30KP33CA-TP

Micro Commercial CoIn Stock: 84830KP33CA-TP Datasheet

MFR RecommendedRFQ

3KP33CA-TP

Micro Commercial CoIn Stock: 9853KP33CA-TP Datasheet

MFR RecommendedRFQ

5KP33CA-TP

Micro Commercial CoIn Stock: 168145KP33CA-TP Datasheet

MFR RecommendedRFQ

BZW50-33B

STMicroelectronicsIn Stock: 10466BZW50-33B Datasheet

MFR RecommendedRFQ

BZW50-33BRL

STMicroelectronicsIn Stock: 2152BZW50-33BRL Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3KP33C-B TVS diode is determined by the following critical parameters:

Voltage Class Compatibility: All substitute parts maintain the 33V reverse standoff voltage specification, ensuring equivalent transient protection threshold.

Clamping Voltage Range: Substitute parts operate within acceptable clamping voltage windows (53.3V to 76V maximum), with lower values providing tighter voltage regulation and higher values offering increased transient energy absorption capability.

Peak Pulse Current & Power Rating: Substitutes are grouped by power dissipation capacity (3kW, 5kW, 15kW, and 30kW), allowing selection based on application transient energy requirements.

Package & Mounting: Substitutes are available in P600 and R-6 axial through-hole packages, maintaining mechanical and electrical compatibility with standard PCB layouts.

Product Status & Compliance: Active substitute parts with ROHS3 compliance and REACH unaffected status ensure regulatory compliance and supply chain continuity.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement (Same Power Rating): The 3KP33CA-TP provides equivalent 3kW power dissipation with matching 56.3A peak pulse current. This part maintains functional parity with the original 3KP33C-B while offering active product status and ROHS3 compliance. Package transition from P600 to R-6 requires PCB layout verification for mechanical fit.

Upgraded Power Capacity (5kW Class): The 5KP33CA-B (Littelfuse) and 5KP33CA-TP (Micro Commercial Co) offer increased transient energy absorption at 5kW rating. Both maintain 33V voltage class and active product status. The Littelfuse variant preserves P600 package compatibility; the Micro Commercial variant uses R-6 package.

High-Energy Applications (15kW & 30kW): The 15KPA33CAE3/TR13 (Microchip Technology) and 15KP33CA-TP (Micro Commercial Co) provide 15kW capacity with active status and full compliance. The 30KP33CA-TP extends to 30kW for maximum transient protection. These selections are appropriate only when application transient energy requirements exceed 3kW.

Alternative Manufacturer (STMicroelectronics TRANSIL™): The BZW50-33B and BZW50-33BRL represent alternative technology from STMicroelectronics with higher clamping voltage (76V) and significantly higher peak pulse current (789A). These parts are suitable for applications requiring enhanced transient suppression but should be evaluated for voltage regulation compatibility.

Compliance & Supply Continuity: All recommended substitutes maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment and supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can the 3KP33CA-TP directly replace the 3KP33C-B without circuit modification?

A: The 3KP33CA-TP maintains identical voltage class (33V), peak pulse current (56.3A), and power rating (3kW), providing functional equivalence. Package transition from P600 to R-6 requires PCB footprint verification. No circuit modification is necessary if mechanical fit is confirmed.

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 differ in physical dimensions and lead spacing. PCB layout compatibility must be verified before substitution. Consult package datasheets for exact dimensional specifications.

Q: When should I select a higher power-rated substitute (5kW, 15kW, or 30kW)?

A: Higher power ratings accommodate greater transient energy without exceeding junction temperature limits. Select based on application transient pulse energy requirements. If the original 3kW rating was adequate, equivalent 3kW substitutes are appropriate. Upgrade only when application analysis indicates higher transient energy exposure.

Q: Are the STMicroelectronics BZW50-33B and BZW50-33BRL interchangeable?

A: Both parts are electrically identical with matching voltage class, clamping voltage, and peak pulse current specifications. The primary difference is packaging format (Cut Tape vs. Tape & Reel). Selection depends on procurement and assembly requirements.

Q: Do all substitute parts meet the same compliance standards as the original?

A: All recommended substitutes are ROHS3 compliant and REACH unaffected. Verify specific compliance requirements for your application and region before final selection.

Q: What is the impact of clamping voltage variation among substitutes?

A: Clamping voltage determines the maximum voltage transient suppression level. Lower clamping voltages (53.3V) provide tighter regulation; higher values (76V) allow greater voltage excursion. Select based on protected circuit voltage tolerance specifications.