3KP40CA Equivalent & Substitute Parts

Part Overview

The 3KP40CA is a bidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient voltage protection applications. This component features a 40V reverse standoff voltage with a 64.5V maximum clamping voltage and 46.5A peak pulse current capability in a through-hole P600 axial package. The product is currently classified as obsolete, making identification of equivalent and substitute parts essential for ongoing system maintenance and new design implementations where this component specification remains applicable.

Substiute Parts

3KP40CA

Littelfuse Inc.In Stock: 11023KP40CA Datasheet

Current PartRFQ

5KP40CA

Diotec SemiconductorIn Stock: 42335KP40CA Datasheet

DirectRFQ

3KP40CA-TP

Micro Commercial CoIn Stock: 10913KP40CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 3KP40CA is determined by strict alignment of the following critical electrical and mechanical parameters:

Electrical Compatibility Criteria:

• Voltage - Reverse Standoff (Typ): 40V
• Voltage - Breakdown (Min): 44.4V
• Voltage - Clamping (Max) @ Ipp: 64.5V
• Bidirectional Channels: 1
• Type: Zener

Mechanical Compatibility Criteria:

• Mounting Type: Through Hole
• Package / Case: Axial configuration

Operational Criteria:

• Operating Temperature Range: -55°C to 175°C (TJ)
• Applications: General Purpose

Substitute parts must maintain identical voltage specifications and clamping characteristics to ensure proper transient suppression performance. Peak pulse current and power ratings may vary within the same voltage class, provided the substitute meets or exceeds the original specification. Package configuration and mounting type must remain consistent for direct board-level replacement without design modification.

Parameter Comparison

Engineering Selection Recommendations

5KP40CA (Diotec Semiconductor): This substitute maintains identical voltage specifications and clamping characteristics while providing enhanced peak pulse current (78A) and power dissipation (5000W) capabilities. The component is in active production status with ROHS3 compliance. The lower minimum operating temperature (-50°C versus -55°C) represents a minor thermal range reduction that does not affect standard industrial applications. This part is suitable for direct electrical substitution where enhanced transient suppression margin is acceptable.

3KP40CA-TP (Micro Commercial Co): This substitute provides electrical equivalence with identical voltage and current specifications to the original 3KP40CA. The component is in active production status with full operating temperature range alignment (-55°C to 175°C). The package designation differs (R-6 versus P600), indicating a potential mechanical variation in lead configuration or spacing that requires verification against board layout specifications before implementation. This part is suitable for applications where original electrical and thermal specifications must be maintained precisely.

Frequently Asked Questions (FAQ)

Q: Can the 5KP40CA replace the 3KP40CA in all applications? A: The 5KP40CA maintains identical voltage specifications and clamping characteristics, making it electrically compatible. The higher peak pulse current (78A) and power rating (5000W) provide additional transient suppression capability. The operating temperature minimum is -50°C instead of -55°C; verify this meets your application requirements. Direct substitution is possible from an electrical standpoint.

Q: What is the difference between the P600 and R-6 packages? A: Both are axial through-hole packages for TVS diodes. The P600 and R-6 designations indicate different lead configurations or spacing specifications. Physical verification against your PCB layout is required before substituting 3KP40CA-TP (R-6 package) for the original 3KP40CA (P600 package) to ensure proper board mounting.

Q: Why is the original 3KP40CA listed as obsolete? A: Obsolete status indicates the manufacturer has discontinued production. The substitute parts listed (5KP40CA and 3KP40CA-TP) are in active production and provide equivalent or superior electrical performance, ensuring continued availability for system maintenance and new implementations.

Q: Are all substitute parts RoHS compliant? A: The 5KP40CA and original 3KP40CA are ROHS3 compliant. The 3KP40CA-TP is listed as REACH Unaffected. Verify compliance requirements for your specific application and regional regulations.

Q: Can I use these parts interchangeably on the same board? A: Electrical interchangeability is confirmed for voltage and current specifications. Mechanical interchangeability depends on package compatibility (P600 versus R-6). Verify PCB layout and lead spacing before mixing different package types on the same assembly.