3KP40C Equivalent & Substitute Parts

Part Overview

The 3KP40C is a transient voltage suppressor (TVS) diode manufactured by Littelfuse, designed for general-purpose voltage protection applications. This component features a 40V reverse standoff voltage with a 67.73V maximum clamping voltage and 46.5A peak pulse current capability in a through-hole P600 axial package. The product is currently obsolete, making identification of suitable substitute components essential for ongoing system maintenance and new design implementations where equivalent performance is required.

Substiute Parts

3KP40C

LittelfuseIn Stock: 10413KP40C Datasheet

Current PartRFQ

5KP40CA

Diotec SemiconductorIn Stock: 42335KP40CA Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3KP40C is determined by the following critical electrical and mechanical parameters:

• Voltage Rating: Reverse standoff voltage of 40V with breakdown minimum of 42.08V
• Clamping Performance: Maximum clamping voltage at peak pulse current
• Peak Pulse Current: Minimum 46.5A capability at 10/1000µs pulse
• Power Dissipation: Peak pulse power rating of 3000W or higher
• Package Compatibility: P600 axial through-hole package for direct board-level replacement
• Diode Type: Zener-type TVS with single bidirectional channel
• Operating Temperature: -55°C to 175°C junction temperature range

The 5KP40CA from Diotec Semiconductor meets all substitution criteria with equivalent voltage ratings, superior peak pulse current (78A), and higher power dissipation (5000W) in the identical P600 axial package.

Parameter Comparison

Engineering Selection Recommendations

The 5KP40CA is a direct substitute for the obsolete 3KP40C based on electrical and mechanical compatibility. Both components are ROHS3 compliant and feature identical P600 axial through-hole packages for direct board-level replacement without layout modifications.

The 5KP40CA offers enhanced performance characteristics with higher peak pulse current (78A versus 46.5A) and greater peak pulse power dissipation (5000W versus 3000W), providing improved transient protection margins in the same physical footprint. The clamping voltage of 64.5V is lower than the original 67.73V, resulting in tighter voltage regulation during transient events.

The operating temperature range of the 5KP40CA (-50°C to 175°C) covers the critical upper temperature specification of the original component, with a 5°C reduction in minimum operating temperature that does not impact typical application requirements.

Frequently Asked Questions (FAQ)

Q: Can the 5KP40CA be used as a direct replacement for the 3KP40C without circuit modifications?

A: Yes. Both components share identical voltage ratings (40V reverse standoff), equivalent diode type (Zener), single bidirectional channel configuration, and identical P600 axial through-hole package. No circuit modifications are required for direct substitution.

Q: What is the significance of the higher peak pulse current in the 5KP40CA?

A: The 5KP40CA provides 78A peak pulse current compared to the 3KP40C's 46.5A. This enhanced capability allows the substitute component to handle larger transient events while maintaining the same voltage protection characteristics, providing additional design margin.

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

A: The 5KP40CA has a maximum clamping voltage of 64.5V compared to the 3KP40C's 67.73V. The lower clamping voltage provides tighter voltage regulation during transient suppression, which is beneficial for protecting sensitive downstream circuitry.

Q: Do both components meet the same compliance standards?

A: Yes. Both the 3KP40C and 5KP40CA are ROHS3 compliant, meeting the same environmental and regulatory requirements for electronic component manufacturing.

Q: What is the minimum operating temperature difference between these parts?

A: The 5KP40CA operates from -50°C minimum compared to the 3KP40C's -55°C minimum. This 5°C difference does not impact typical industrial or commercial applications and both components maintain the same 175°C maximum junction temperature.