Equivalent & Substitute Parts for 3KP40A TVS Diode

Part Overview

The 3KP40A is a unidirectional 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 3KP40A is classified as obsolete. Equivalent and substitute parts are available from active product lines that maintain the same electrical and mechanical specifications, ensuring continued availability for new designs and replacement applications.

Substiute Parts

3KP40A

Littelfuse Inc.In Stock: 30133KP40A Datasheet

Current PartRFQ

5KP40A

Diotec SemiconductorIn Stock: 34645KP40A Datasheet

DirectRFQ

15KP40A-TP

Micro Commercial CoIn Stock: 107315KP40A-TP Datasheet

MFR RecommendedRFQ

3KP40A-TP

Micro Commercial CoIn Stock: 7783KP40A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 3KP40A TVS diode are qualified based on the following electrical and mechanical parameters:

Critical Matching Parameters:

• Voltage - Reverse Standoff (Typ): 40V
• Voltage - Breakdown (Min): 44.4V minimum
• Voltage - Clamping (Max) @ Ipp: 64.5V or lower
• Unidirectional configuration (1 channel)
• Type: Zener diode
• Mounting Type: Through Hole
• Operating Temperature Range: -55°C to 175°C or equivalent

Allowable Variations:

• Peak Pulse Current: May exceed 46.5A (higher current capability is acceptable)
• Power - Peak Pulse: May exceed 3000W (higher power rating is acceptable)
• Package / Case: P600 or R-6 axial packages are mechanically compatible
• Manufacturer: Different manufacturers acceptable if electrical specifications are met
• Product Status: Active products preferred for long-term availability

Parameter Comparison

Engineering Selection Recommendations

5KP40A (Diotec Semiconductor): This substitute provides identical voltage specifications and P600 axial package compatibility. The 5KP40A offers higher peak pulse current (78A) and power dissipation (5000W), making it suitable for applications requiring enhanced transient protection margin. Product status is active, ensuring long-term availability. ROHS3 compliance is maintained.

15KP40A-TP (Micro Commercial Co): This manufacturer-recommended substitute maintains all critical voltage parameters with a slightly higher clamping voltage (65.8V). The 15KP40A-TP provides significantly higher power dissipation (15000W), suitable for high-energy transient environments. The R-6 axial package is mechanically compatible with through-hole PCB layouts. Product status is active with ROHS3 compliance and REACH unaffected status.

3KP40A-TP (Micro Commercial Co): This direct electrical equivalent from Micro Commercial Co matches the 3KP40A specifications exactly, including 46.5A peak pulse current and 3000W power dissipation. The R-6 axial package provides mechanical compatibility. Product status is active, ensuring availability. ROHS3 compliance and REACH unaffected status are confirmed.

All substitute parts maintain ROHS3 compliance and are suitable for general-purpose transient voltage suppression applications across the specified operating temperature range.

Frequently Asked Questions (FAQ)

Q: Can the 5KP40A replace the 3KP40A in my circuit? A: Yes. The 5KP40A maintains identical voltage specifications (40V standoff, 44.4V breakdown minimum, 64.5V clamping maximum) and uses the same P600 axial through-hole package. The higher current and power ratings provide additional protection margin without affecting circuit compatibility.

Q: What is the difference between the P600 and R-6 packages? A: Both P600 and R-6 are axial through-hole packages formats for TVS diodes. They are mechanically compatible for PCB mounting. The primary difference is the physical dimensions and lead spacing. Verify PCB footprint compatibility before substitution.

Q: Is the 15KP40A-TP suitable for my application if I only need 3000W protection? A: Yes. The 15KP40A-TP exceeds the power requirement and maintains all critical voltage parameters. Higher power rating provides additional safety margin and does not negatively impact circuit performance. The component will operate within specification at lower power levels.

Q: Why is the 3KP40A obsolete? A: The 3KP40A from Littelfuse Inc. is classified as obsolete. Active equivalent products from other manufacturers (Diotec Semiconductor and Micro Commercial Co) provide identical or superior electrical specifications and are recommended for new designs and replacements.

Q: Are all substitute parts ROHS3 compliant? A: Yes. All listed substitute parts (5KP40A, 15KP40A-TP, and 3KP40A-TP) are ROHS3 compliant, meeting environmental and regulatory requirements equivalent to the original 3KP40A.

Q: Can I use the 3KP40A-TP as a direct replacement? A: Yes. The 3KP40A-TP from Micro Commercial Co is a direct electrical equivalent with identical voltage and current specifications. The R-6 axial package is mechanically compatible with standard through-hole PCB layouts designed for the original P600 package.

Q: What is the operating temperature range for substitute parts? A: The 5KP40A operates from -50°C to 175°C. The 15KP40A-TP and 3KP40A-TP both operate from -55°C to 175°C, matching or exceeding the original 3KP40A specification of -55°C to 175°C.