3KP18CA-B Equivalent & Substitute Parts

Part Overview

The 3KP18CA-B is a Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose voltage transient protection applications. This component features an 18V reverse standoff voltage with a 29.2V maximum clamping voltage and 102.7A peak pulse current capability. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity.

Substiute Parts

3KP18CA-B

Littelfuse Inc.In Stock: 8213KP18CA-B Datasheet

Current PartRFQ

5KP18CA-B

Littelfuse Inc.In Stock: 7835KP18CA-B Datasheet

DirectRFQ

15KP18CA-TP

Micro Commercial CoIn Stock: 129215KP18CA-TP Datasheet

MFR RecommendedRFQ

3KP18CA-TP

Micro Commercial CoIn Stock: 10323KP18CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 3KP18CA-B is determined by the following critical electrical and mechanical parameters:

• Reverse standoff voltage: 18V (required match)
• Breakdown voltage minimum: 20V (required match)
• Clamping voltage maximum: 29.2V or lower (acceptable tolerance)
• Peak pulse current: 102.7A or higher (acceptable if equal or greater)
• Peak pulse power: 3000W or higher (acceptable if equal or greater)
• Operating temperature range: -55°C to 175°C (required match)
• Mounting type: Through Hole (required match)
• Package type: P600 or R-6 axial (mechanically compatible)
• Type: Zener (required match)
• Bidirectional channels: 1 (required match)

Three substitute parts meet these criteria with varying power ratings and packaging options.

Parameter Comparison

Engineering Selection Recommendations

5KP18CA-B (Littelfuse Inc.): This part is the direct electrical equivalent with identical voltage and clamping specifications. It maintains the same P600 axial package and offers active product status with higher peak pulse current (174.7A) and power rating (5000W), providing enhanced transient protection margin. ROHS3 compliance is maintained.

3KP18CA-TP (Micro Commercial Co): This part provides identical electrical specifications to the original 3KP18CA-B with matching 102.7A peak pulse current and 3000W power rating. It features active product status and ROHS3 compliance. The package transitions from P600 to R-6 axial format, which is mechanically compatible for through-hole mounting applications.

15KP18CA-TP (Micro Commercial Co): This part offers the highest power rating (15000W) while maintaining the required 18V standoff and 20V minimum breakdown voltages. The clamping voltage increases to 30.9V, which remains within acceptable tolerance for general-purpose transient suppression. Active product status and ROHS3 compliance are confirmed. The R-6 axial package is mechanically compatible.

All substitute parts maintain ROHS3 compliance and the required operating temperature range of -55°C to 175°C.

Frequently Asked Questions (FAQ)

Q: Can 5KP18CA-B replace 3KP18CA-B in all applications?

A: Yes. The 5KP18CA-B maintains identical voltage specifications (18V standoff, 20V breakdown, 29.2V clamping) and package format (P600 axial). The higher peak pulse current (174.7A vs. 102.7A) and power rating (5000W vs. 3000W) provide equivalent or superior performance in transient suppression circuits.

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

A: Both are through-hole axial packages suitable for PCB mounting. P600 and R-6 are mechanically compatible form factors for axial lead components. Component selection between these packages depends on PCB layout constraints and lead spacing requirements.

Q: Is the 15KP18CA-TP suitable as a direct replacement?

A: The 15KP18CA-TP meets all critical electrical parameters: 18V standoff voltage, 20V minimum breakdown, and maintains the required operating temperature range. The clamping voltage increases to 30.9V, which is acceptable for general-purpose applications. The significantly higher power rating (15000W) provides enhanced protection capability.

Q: Are all substitute parts RoHS compliant?

A: Yes. All substitute parts listed (5KP18CA-B, 15KP18CA-TP, and 3KP18CA-TP) are ROHS3 compliant, matching the compliance status of the original 3KP18CA-B.

Q: Why is the original 3KP18CA-B marked as obsolete?

A: Obsolete status indicates the part is no longer manufactured by Littelfuse Inc. Active equivalent parts from Littelfuse (5KP18CA-B) and Micro Commercial Co (3KP18CA-TP, 15KP18CA-TP) provide continued design support and procurement availability.