5KP40A-B Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The 5KP40A-B is an active Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient voltage protection applications. This unidirectional zener diode operates with a 40V reverse standoff voltage and provides peak pulse power dissipation of 5000W. The component is housed in a P600 axial through-hole package and maintains full operational capability across the -55°C to 175°C temperature range. Finding equivalent or substitute parts may be necessary due to inventory constraints, supply chain considerations, or specific packaging requirements while maintaining electrical performance within acceptable parameters.

Key Parameters

Parameter	Value	Unit
Voltage - Reverse Standoff (Typ)	40	V
Voltage - Breakdown (Min)	44.4	V
Voltage - Clamping (Max) @ Ipp	64.5	V
Current - Peak Pulse (10/1000µs)	79.1	A
Power - Peak Pulse	5000	W
Operating Temperature Range	-55 to 175	°C
Mounting Type	Through Hole	-
Package / Case	P600, Axial	-
Type	Zener	-
Unidirectional Channels	1	-

Substitute Part Grouping Explanation

Substitution eligibility for the 5KP40A-B is determined by the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

Voltage - Reverse Standoff (Typ): 40V nominal
Voltage - Breakdown (Min): 44.4V minimum
Voltage - Clamping (Max) @ Ipp: 64.5V maximum
Power - Peak Pulse: 5000W (5kW) minimum
Unidirectional Channels: 1 channel
Type: Zener diode
Mounting Type: Through Hole
Operating Temperature Range: -55°C to 175°C minimum

Secondary Considerations:

Package / Case: P600 or equivalent axial through-hole packages
RoHS3 Compliance: Required
Moisture Sensitivity Level (MSL): 1 (Unlimited)

Parts meeting all primary criteria are classified as direct electrical equivalents. Parts meeting primary electrical criteria but differing in package type or power rating are classified as functional substitutes with noted trade-offs.

Parameter Comparison

Parameter	5KP40A-B (Littelfuse)	5KP40A (Diotec)	5KP40A-TP (Micro Commercial Co)	1.5KE47A (Taiwan Semiconductor)	1.5KE51A (Meritek)	P6KE51A (Fairchild)
Voltage - Reverse Standoff (Typ)	40V	40V	40V	40.2V	-	-
Voltage - Breakdown (Min)	44.4V	44.4V	44.4V	44.7V	48.5V	-
Voltage - Clamping (Max) @ Ipp	64.5V	64.5V	64.5V	64.8V	70.1V	-
Current - Peak Pulse (10/1000µs)	79.1A	78A	-	24A	21.7A	-
Power - Peak Pulse	5000W	5000W	5000W	1500W	1500W	-
Operating Temperature Range	-55 to 175°C	-50 to 175°C	-55 to 175°C	-55 to 175°C	-55 to 175°C	-
Package / Case	P600, Axial	P600, Axial	R-6, Axial	DO-201AA, Axial	DO-201, Axial	-
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	-
Type	Zener	Zener	Zener	Zener	Zener	-
Unidirectional Channels	1	1	1	1	1	-
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	-	-

Engineering Selection Recommendations

Direct Electrical Equivalents (5000W Power Rating):

The 5KP40A (Diotec Semiconductor) and 5KP40A-TP (Micro Commercial Co) are direct electrical equivalents to the 5KP40A-B. Both maintain identical voltage specifications (40V reverse standoff, 44.4V breakdown minimum, 64.5V clamping maximum) and 5000W peak pulse power dissipation. The 5KP40A-TP differs only in package designation (R-6 versus P600) but maintains equivalent axial through-hole form factor compatibility. Both alternatives are ROHS3 compliant and rated for -55°C to 175°C operation. Selection between these options depends on packaging availability and PCB footprint requirements.

Functional Substitutes (1500W Power Rating):

The 1.5KE47A (Taiwan Semiconductor Corporation) and 1.5KE51A (Meritek) are functional substitutes with reduced peak pulse power dissipation (1500W versus 5000W). The 1.5KE47A maintains voltage specifications within acceptable tolerance (40.2V standoff, 44.7V breakdown, 64.8V clamping) but operates at 24A peak pulse current. The 1.5KE51A exhibits higher clamping voltage (70.1V) and lower peak pulse current (21.7A), representing a trade-off in transient suppression characteristics. These parts are suitable only for applications where peak pulse power requirements do not exceed 1500W. Both use DO-201 axial through-hole packages and maintain the -55°C to 175°C operating temperature range.

Limited Data Substitute:

The P6KE51A (Fairchild Semiconductor) is listed as a substitute but lacks sufficient electrical parameter documentation in the provided data set. This part cannot be evaluated against the primary substitution criteria and should not be selected without obtaining complete electrical specifications from the manufacturer.

Compliance Status:

All recommended direct equivalents (5KP40A, 5KP40A-TP) maintain ROHS3 compliance, MSL Level 1 (Unlimited), and REACH unaffected status consistent with the 5KP40A-B. The 1.5KE47A maintains equivalent compliance certifications. Selection of any substitute part should confirm compliance requirements for the target application.

Frequently Asked Questions (FAQ)

Q: Can the 1.5KE47A or 1.5KE51A be used as direct replacements for the 5KP40A-B?

A: The 1.5KE series parts are functional substitutes only, not direct replacements. While they maintain compatible voltage specifications and through-hole mounting, their peak pulse power dissipation is limited to 1500W compared to the 5000W rating of the 5KP40A-B. Selection of these parts is appropriate only when application transient energy levels do not exceed 1500W. Peak pulse current is also significantly reduced (24A and 21.7A respectively versus 79.1A), which may affect suppression effectiveness in high-current transient events.

Q: What is the difference between the 5KP40A and 5KP40A-TP packages?

A: Both parts are electrically identical with matching voltage and power specifications. The primary difference is package designation: the 5KP40A uses P600 axial packaging while the 5KP40A-TP uses R-6 axial packaging. Both are through-hole components with equivalent form factors. Package selection depends on PCB footprint design and component availability. Verify footprint compatibility with your PCB layout before substitution.

Q: Are all substitute parts ROHS3 compliant?

A: The 5KP40A (Diotec), 5KP40A-TP (Micro Commercial Co), and 1.5KE47A (Taiwan Semiconductor) are confirmed ROHS3 compliant. The 1.5KE51A (Meritek) compliance status is not specified in the provided data. The P6KE51A (Fairchild) compliance information is not available. Verify ROHS3 compliance status with the manufacturer before selecting parts for applications requiring regulatory compliance.

Q: What is the operating temperature range for substitute parts?

A: The 5KP40A-B, 5KP40A-TP, 1.5KE47A, and 1.5KE51A all operate across the -55°C to 175°C temperature range. The 5KP40A (Diotec) has a slightly reduced lower temperature limit of -50°C. For applications requiring full -55°C operation, confirm the selected substitute part meets this specification.

Q: Can I substitute the 5KP40A-B with the P6KE51A?

A: The P6KE51A cannot be evaluated as a substitute due to incomplete electrical parameter data in the provided specifications. Critical parameters including voltage ratings, peak pulse current, and power dissipation are not documented. Obtain complete electrical specifications from Fairchild Semiconductor before considering this part for substitution.

Q: How do I determine which substitute part is appropriate for my application?

A: Selection depends on three primary factors: (1) Peak pulse power requirement—if your application requires 5000W dissipation, select 5KP40A or 5KP40A-TP; if limited to 1500W, the 1.5KE series is acceptable. (2) Package compatibility—verify the axial through-hole package (P600, R-6, or DO-201) fits your PCB footprint. (3) Compliance requirements—confirm ROHS3 and other regulatory certifications match your application standards. All direct equivalents maintain identical voltage specifications (40V standoff, 44.4V breakdown, 64.5V clamping).

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