5KP40 Transient Voltage Suppressor (TVS) Equivalent & Substitute Parts

Part Overview

The 5KP40 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, 5000W peak pulse power rating, and P600 axial through-hole packaging. The 5KP40 is classified as obsolete, necessitating identification of active equivalent and substitute parts that maintain electrical and mechanical compatibility for ongoing circuit protection requirements.

Key Parameters

Parameter	Value
Manufacturer Part Number	5KP40
Manufacturer	Littelfuse Inc.
Category	Transient Voltage Suppressors (TVS)
Type	Zener
Unidirectional Channels	1
Voltage - Reverse Standoff (Typ)	40V
Voltage - Breakdown (Min)	42.08V
Voltage - Clamping (Max) @ Ipp	67.73V
Power - Peak Pulse	5000W (5kW)
Operating Temperature Range	-55°C ~ 175°C (TJ)
Mounting Type	Through Hole
Package / Case	P600, Axial
RoHS Status	ROHS3 Compliant
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution of the 5KP40 is determined by the following critical parameters:

Primary Substitution Criteria:

Voltage - Reverse Standoff (Typ): 40V ± tolerance
Voltage - Breakdown (Min): 42.08V to 48.5V range
Voltage - Clamping (Max) @ Ipp: 64.5V to 71.4V range
Power - Peak Pulse: 5000W minimum (5kW class)
Unidirectional Channels: 1
Type: Zener
Operating Temperature: -55°C minimum to 175°C maximum
Mounting Type: Through Hole
RoHS Status: ROHS3 Compliant

Secondary Compatibility Factors:

Package / Case: P600 axial preferred; R-6 and DO-201 axial packages acceptable with mechanical verification
Current - Peak Pulse (10/1000µs): Minimum 70A for P600 package variants

Substitute parts are grouped into two categories: direct electrical equivalents (5KP40A, SLD40U-017-B, 5KP40E3/TR13, 15KP40A-TP) and functional alternatives with reduced power ratings (1.5KE47A, 1.5KE51A, SA40A-TP) suitable for lower-energy transient protection scenarios.

Parameter Comparison

Parameter	5KP40 (Main)	5KP40A	SLD40U-017-B	5KP40E3/TR13	15KP40A-TP	1.5KE47A	SA40A-TP
Manufacturer	Littelfuse Inc.	Diotec Semiconductor	Littelfuse Inc.	Microchip Technology	Micro Commercial Co	Taiwan Semiconductor Corporation	Micro Commercial Co
Product Status	Obsolete	Active	Active	Active	Active	Active	Active
Type	Zener	Zener	Zener	Zener	Zener	Zener	Zener
Unidirectional Channels	1	1	1	1	1	1	1
Voltage - Reverse Standoff (Typ)	40V	40V	40V	40V	40V	40.2V	40V
Voltage - Breakdown (Min)	42.08V	44.4V	44.4V	44.4V	44.4V	44.7V	44.4V
Voltage - Clamping (Max) @ Ipp	67.73V	64.5V	64.5V	71.4V	65.8V	64.8V	64.5V
Current - Peak Pulse (10/1000µs)	-	78A	79.1A	70A	-	24A	7.9A
Power - Peak Pulse	5000W (5kW)	5000W (5kW)	5000W (5kW)	5000W (5kW)	15000W (15kW)	1500W (1.5kW)	500W
Operating Temperature Range	-55°C ~ 175°C	-50°C ~ 175°C	-55°C ~ 175°C	-55°C ~ 175°C	-55°C ~ 175°C	-55°C ~ 175°C	-55°C ~ 175°C
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole
Package / Case	P600, Axial	P600, Axial	P600, Axial	P600, Axial	R-6, Axial	DO-201AA, DO-27, Axial	DO-204AC, DO-15, Axial
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	Not specified

Engineering Selection Recommendations

Direct Electrical Equivalents (5kW Class, 40V Standoff):

The 5KP40A (Diotec Semiconductor), SLD40U-017-B (Littelfuse Inc.), and 5KP40E3/TR13 (Microchip Technology) are active products that maintain the 5000W power rating, 40V reverse standoff voltage, and P600 axial package configuration. All three are ROHS3 compliant and operate across the -55°C to 175°C temperature range. The 5KP40A offers the widest availability (3400 pcs in stock) and represents the most direct replacement. The SLD40U-017-B carries AEC-Q101 automotive qualification and is suitable for automotive-grade applications. The 5KP40E3/TR13 provides the highest clamping voltage (71.4V) within the 5kW class.

Higher Power Alternative (15kW Class):

The 15KP40A-TP (Micro Commercial Co) provides 15000W peak pulse power in R-6 axial packaging with identical 40V standoff voltage and -55°C to 175°C operating range. This part offers enhanced transient protection margin but requires mechanical verification for R-6 package compatibility in existing P600 footprints.

Reduced Power Alternatives (1.5kW Class):

The 1.5KE47A (Taiwan Semiconductor Corporation) and 1.5KE51A (Meritek) operate at 1500W peak pulse power with 40V-class standoff voltages and DO-201 axial packaging. These parts are suitable for lower-energy transient protection applications where 5kW power rating is not required. The 1.5KE47A offers high inventory availability (36829 pcs).

Lower Power Alternative (500W Class):

The SA40A-TP (Micro Commercial Co) provides 500W peak pulse power in DO-15 axial packaging with 40V standoff voltage. This part is applicable only to low-energy transient suppression scenarios and represents a significant power derating from the original 5KP40 specification.

Frequently Asked Questions (FAQ)

Q: Can the 5KP40A directly replace the 5KP40 in existing designs?

A: Yes. The 5KP40A maintains identical electrical parameters (40V standoff, 5000W power rating, 64.5V clamping voltage) and P600 axial through-hole packaging. Both are ROHS3 compliant and operate across -55°C to 175°C. The primary difference is manufacturer (Diotec vs. Littelfuse) and active product status.

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

A: Both are axial through-hole packages for TVS diodes. P600 is the standard package for 5kW-class devices; R-6 is used for higher power ratings (15kW class). Physical dimensions differ, requiring mechanical verification before substitution in existing PCB layouts.

Q: Can I use the 1.5KE47A as a substitute for the 5KP40?

A: The 1.5KE47A is electrically compatible (40V standoff, similar clamping voltage) but provides only 1500W peak pulse power versus the 5KP40's 5000W rating. Use only if your application requires lower transient energy suppression. The DO-201 package differs from P600, requiring PCB layout modification.

Q: Is the SLD40U-017-B suitable for automotive applications?

A: Yes. The SLD40U-017-B carries AEC-Q101 automotive qualification and is graded for automotive use. It maintains 5000W power rating, 40V standoff voltage, and P600 packaging identical to the 5KP40.

Q: What does ROHS3 compliance mean for this component?

A: ROHS3 compliance indicates the part meets Restriction of Hazardous Substances Directive requirements, restricting lead, cadmium, mercury, and other hazardous materials. All recommended direct equivalents are ROHS3 compliant.

Q: Why is the 5KP40 obsolete?

A: The 5KP40 is listed as obsolete by Littelfuse Inc. Active equivalent products (5KP40A, SLD40U-017-B, 5KP40E3/TR13) are available from alternative manufacturers and should be used for new designs and ongoing production.

Q: Can I use the 15KP40A-TP for higher transient protection?

A: Yes. The 15KP40A-TP provides 15000W peak pulse power (3x the 5KP40 rating) with identical 40V standoff voltage. However, R-6 packaging differs from P600, requiring mechanical verification and potential PCB redesign.

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