Equivalent & Substitute Parts for 3KP18C

Part Overview

The 3KP18C is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose voltage protection applications. This bidirectional Zener diode features an 18V reverse standoff voltage with a 30.66V maximum clamping voltage and 102.7A peak pulse current capability in a P600 axial package. The product is currently obsolete, making identification of suitable substitute components essential for ongoing system maintenance and new design implementations.

Substiute Parts

3KP18C

Littelfuse Inc.In Stock: 11673KP18C Datasheet

Current PartRFQ

5KP18CA

Diotec SemiconductorIn Stock: 61755KP18CA Datasheet

DirectRFQ

15KP18CA-TP

Micro Commercial CoIn Stock: 129215KP18CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 3KP18C are selected based on strict electrical and mechanical compatibility criteria. The primary substitution parameters are:

• Voltage - Reverse Standoff: 18V (exact match required)
• Voltage - Breakdown (Min): 18.95V minimum
• Package / Case: P600 or R-6 axial through-hole packages
• Bidirectional Channels: 1 (single channel)
• Type: Zener diode
• RoHS Compliance: ROHS3 Compliant

The identified substitute parts maintain the core 18V standoff voltage specification while offering equal or superior performance characteristics in clamping voltage, peak pulse current, and power dissipation ratings. All substitutes are active products with current manufacturing status and full compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts meet the electrical requirements for 18V TVS diode applications and maintain full ROHS3 compliance. The 5KP18CA from Diotec Semiconductor provides a direct package match (P600 axial) with enhanced power dissipation (5000W versus 3000W) and higher peak pulse current (171A versus 102.7A). The 15KP18CA-TP from Micro Commercial Co offers the highest power rating (15000W) with a compatible R-6 axial package and maintains the full -55°C to 175°C operating temperature range of the original part.

Selection between these substitutes depends on application-specific power dissipation requirements and available board space for package accommodation. Both parts are currently in active production with established supply chains.

Frequently Asked Questions (FAQ)

Q: Can the 5KP18CA directly replace the 3KP18C without circuit modifications?

A: Yes. The 5KP18CA maintains the 18V reverse standoff voltage and is packaged in the same P600 axial format. The enhanced power rating (5000W versus 3000W) and higher peak pulse current provide equal or superior protection performance in the same footprint.

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

A: Both are through-hole axial packages for TVS diodes. The P600 and R-6 are mechanically compatible for board mounting, though they may have different lead spacing or physical dimensions. Verify PCB pad spacing before substituting between package types.

Q: Why does the 15KP18CA-TP have a higher power rating?

A: The 15KP18CA-TP is rated for 15000W peak pulse power, compared to 3000W for the 3KP18C. This higher rating indicates greater transient energy absorption capability, making it suitable for applications requiring enhanced surge protection.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. Both the 5KP18CA and 15KP18CA-TP are ROHS3 compliant, matching the compliance status of the original 3KP18C.

Q: What is the minimum breakdown voltage difference between parts?

A: The 3KP18C has a minimum breakdown voltage of 18.95V, while both substitutes specify 20V minimum. This 1.05V difference is within acceptable tolerance for general-purpose TVS applications with 18V standoff specifications.