3KP78C Equivalent & Substitute Parts

Part Overview

The 3KP78C is a bidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient voltage protection applications. This component features a 78V reverse standoff voltage rating and 3000W peak pulse power handling capability in a through-hole P600 axial package. The 3KP78C is classified as obsolete, making identification of suitable substitute components essential for ongoing design support and production continuity.

Substiute Parts

3KP78C

Littelfuse Inc.In Stock: 9933KP78C Datasheet

Current PartRFQ

5KP78CA

Littelfuse Inc.In Stock: 33025KP78CA Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3KP78C is determined by the following critical electrical and mechanical parameters:

Voltage Parameters: The reverse standoff voltage (78V typical) and breakdown voltage range (82.13V minimum) establish the primary voltage protection threshold. Substitute components must maintain identical or equivalent voltage ratings to ensure proper circuit protection without nuisance triggering.

Power Handling: The 3000W peak pulse power rating defines the transient energy dissipation capability. Substitute parts with equal or higher power ratings provide equivalent or improved performance.

Package Compatibility: The P600 axial through-hole package is a mechanical requirement for board-level integration. Substitute components must use the identical package to ensure direct replacement without PCB redesign.

Bidirectional Configuration: The single bidirectional channel configuration must be preserved in substitute components.

Temperature Range: The operating temperature range of -55°C to 175°C (TJ) must be maintained or exceeded.

The 5KP78CA meets all substitution criteria while offering enhanced performance characteristics and active product status.

Parameter Comparison

Engineering Selection Recommendations

The 5KP78CA is the qualified substitute for the 3KP78C based on the following engineering criteria:

Voltage Compatibility: Both components share the identical 78V reverse standoff voltage rating, ensuring equivalent circuit protection thresholds. The 5KP78CA exhibits a slightly higher minimum breakdown voltage (86.7V vs. 82.13V) and lower maximum clamping voltage (126V vs. 132.3V), both of which represent improved performance characteristics within acceptable engineering tolerances.

Power Rating Enhancement: The 5KP78CA provides 5000W peak pulse power handling compared to the 3KP78C's 3000W rating, delivering 67% additional transient energy dissipation capacity. This enhanced capability provides design margin for transient protection without requiring circuit modifications.

Package Equivalence: Both components utilize the P600 axial through-hole package, enabling direct mechanical and electrical substitution without PCB redesign.

Compliance and Availability: The 5KP78CA maintains ROHS3 compliance and active product status, ensuring long-term supply chain availability and regulatory compliance. The 3KP78C's obsolete status necessitates transition to an active equivalent.

Temperature Range: Both components operate across the identical -55°C to 175°C temperature range, maintaining thermal performance specifications.

Frequently Asked Questions (FAQ)

Q: Can the 5KP78CA directly replace the 3KP78C without circuit modifications?

A: Yes. Both components share identical voltage ratings (78V reverse standoff), bidirectional configuration, P600 axial package, and operating temperature range. Direct substitution is supported without PCB or schematic changes.

Q: What is the significance of the higher power rating in the 5KP78CA?

A: The 5KP78CA's 5000W peak pulse rating versus the 3KP78C's 3000W rating provides enhanced transient energy handling. This represents an improvement in performance margin and does not create compatibility issues in applications designed for the 3KP78C.

Q: Are there differences in clamping voltage between these components?

A: The 5KP78CA exhibits a maximum clamping voltage of 126V compared to the 3KP78C's 132.3V. This lower clamping voltage represents improved transient suppression performance and remains within acceptable engineering tolerances for equivalent substitution.

Q: Why is product status relevant to component selection?

A: The 3KP78C's obsolete status indicates discontinued manufacturing and limited future availability. The 5KP78CA's active status ensures ongoing supply chain support, manufacturing consistency, and regulatory compliance for current and future production requirements.

Q: Are packaging considerations identical between these components?

A: Yes. Both the 3KP78C and 5KP78CA use the P600 axial through-hole package. The main packaging difference is that the 5KP78CA is supplied in Tape & Reel format, which is standard for active production components and does not affect electrical or mechanical compatibility.

Q: Do both components meet current regulatory requirements?

A: Yes. Both the 3KP78C and 5KP78CA are ROHS3 compliant, meeting current environmental and regulatory standards for electronic component manufacturing and use.