Littelfuse 3KP48-B Transient Voltage Suppressor Equivalent & Substitute Parts

Part Overview

The Littelfuse 3KP48-B is a unidirectional Zener transient voltage suppressor (TVS) diode designed for general-purpose overvoltage protection applications. This through-hole axial component operates across a temperature range of -55°C to 175°C and is ROHS3 compliant. The 3KP48-B is classified as obsolete, necessitating identification of active equivalent and substitute parts that maintain electrical and mechanical compatibility for new designs and ongoing production requirements.

Key Parameters

Parameter	Value
Voltage - Reverse Standoff (Typ)	48V
Voltage - Breakdown (Min)	50.49V
Voltage - Clamping (Max) @ Ipp	81.27V
Current - Peak Pulse (10/1000µs)	38.8A
Power - Peak Pulse	3000W
Operating Temperature	-55°C ~ 175°C (TJ)
Mounting Type	Through Hole
Package / Case	P600, Axial
Type	Zener
Unidirectional Channels	1
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution of the 3KP48-B is determined by the following critical parameters:

Electrical Compatibility Requirements:

Voltage - Reverse Standoff (Typ): 48V
Voltage - Breakdown (Min): 50.49V minimum
Voltage - Clamping (Max) @ Ipp: Must not exceed application limits
Current - Peak Pulse (10/1000µs): Must meet or exceed 38.8A
Power - Peak Pulse: Must meet or exceed 3000W
Operating Temperature: -55°C ~ 175°C (TJ)

Mechanical Compatibility Requirements:

Mounting Type: Through Hole
Unidirectional Channels: 1
Type: Zener

Compliance Requirements:

RoHS Status: ROHS3 Compliant

Substitute parts are grouped into two categories based on power rating and current handling capacity: 5kW-rated devices (5KP series) and higher-power devices (15KP and 30KP series). All substitutes maintain the 48V reverse standoff voltage and operate within the specified temperature range.

Parameter Comparison

Part Number	Manufacturer	Voltage - Reverse Standoff (Typ)	Voltage - Breakdown (Min)	Voltage - Clamping (Max) @ Ipp	Current - Peak Pulse (10/1000µs)	Power - Peak Pulse	Package / Case	Product Status
3KP48-B	Littelfuse Inc.	48V	50.49V	81.27V	38.8A	3000W	P600, Axial	Obsolete
5KP48A-B	Littelfuse	48V	53.3V	77.4V	65.9A	5000W	P600, Axial	Active
5KP48A-E3/54	Vishay General Semiconductor - Diodes Division	48V	53.3V	77.4V	64.6A	5000W	P600, Axial	Active
5KP48A-E3/73	Vishay General Semiconductor - Diodes Division	48V	53.3V	77.4V	64.6A	5000W	P600, Axial	Active
5KP48A-TP	Micro Commercial Co	48V	53.3V	77.4V	—	5000W	R-6, Axial	Active
5KP48AHE3/54	Vishay General Semiconductor - Diodes Division	48V	53.3V	77.4V	64.6A	5000W	P600, Axial	Active
5KP48AHE3/73	Vishay General Semiconductor - Diodes Division	48V	53.3V	77.4V	64.6A	5000W	P600, Axial	Active
15KP48A-TP	Micro Commercial Co	48V	53.3V	77.7V	—	15000W	R-6, Axial	Active
15KPA48AE3/TR13	Microchip Technology	48V	53.6V	77.7V	194.3A	15000W	P600, Axial	Active
30KP48A-TP	Micro Commercial Co	48V	53.6V	81.6V	—	30000W	R-6, Axial	Active

Engineering Selection Recommendations

Primary Substitutes (Direct Replacement Category):

The 5KP48A series devices (5KP48A-B, 5KP48A-E3/54, 5KP48A-E3/73, 5KP48AHE3/54, 5KP48AHE3/73) are the most direct substitutes for the 3KP48-B. These parts maintain the 48V reverse standoff voltage, operate within the same temperature range (-55°C to 175°C), and are ROHS3 compliant. The 5KP48A series provides increased current handling (64.6A to 65.9A) and power dissipation (5000W) compared to the 3KP48-B (38.8A, 3000W), making them suitable for applications requiring enhanced transient protection.

Vishay TransZorb® Series (5KP48A-E3/54, 5KP48A-E3/73, 5KP48AHE3/54, 5KP48AHE3/73):

These Vishay devices are active products with ROHS3 compliance and REACH unaffected status. The automotive-qualified variants (5KP48AHE3/54, 5KP48AHE3/73) carry AEC-Q101 certification and are suitable for applications requiring automotive-grade reliability. All variants maintain P600 axial packaging for direct board-level compatibility.

Higher Power Alternatives (15KP and 30KP Series):

For applications requiring enhanced transient suppression capability, the 15KP48A-TP (Micro Commercial Co, 15000W) and 15KPA48AE3/TR13 (Microchip Technology, 15000W) provide significantly increased power dissipation while maintaining the 48V standoff voltage. The 30KP48A-TP (Micro Commercial Co, 30000W) offers maximum protection for severe transient environments. These higher-power devices are active products with full ROHS3 compliance and REACH unaffected status.

Package Considerations:

Most 5KP series substitutes are available in P600 axial packaging, maintaining mechanical compatibility with the original 3KP48-B. Micro Commercial Co variants (5KP48A-TP, 15KP48A-TP, 30KP48A-TP) use R-6 axial packaging, which differs mechanically but maintains through-hole mounting compatibility.

Frequently Asked Questions (FAQ)

Q: Can I use a 5KP48A series device as a direct replacement for the 3KP48-B?

A: Yes. The 5KP48A series maintains the critical 48V reverse standoff voltage and operates within the same temperature range. All 5KP48A variants are active products with ROHS3 compliance. The increased current and power ratings (64.6A to 65.9A, 5000W) provide enhanced protection compared to the 3KP48-B (38.8A, 3000W).

Q: What is the difference between 5KP48A-E3/54 and 5KP48A-E3/73?

A: Both parts are electrically identical Vishay TransZorb® devices with identical electrical specifications (48V standoff, 77.4V clamping, 64.6A peak pulse, 5000W power). The suffix designations (54 and 73) indicate different packaging or tape configurations but do not affect electrical performance or compatibility.

Q: Are the automotive-qualified variants (5KP48AHE3/54, 5KP48AHE3/73) suitable for non-automotive applications?

A: Yes. The automotive-qualified variants carry AEC-Q101 certification and meet automotive reliability standards, making them suitable for any application requiring equivalent or higher reliability. These parts are fully compatible with general-purpose applications.

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

A: Both are through-hole axial packages suitable for PCB mounting. P600 is the standard axial package used by Littelfuse and Vishay. R-6 is an alternative axial package used by Micro Commercial Co. Both packages are mechanically compatible with standard through-hole PCB layouts, though physical dimensions may vary slightly.

Q: Should I use a 15KP or 30KP series device instead of a 5KP series substitute?

A: Selection depends on application requirements. The 5KP48A series (5000W) is suitable for general-purpose transient suppression matching or exceeding the 3KP48-B capability. The 15KP48A series (15000W) and 30KP48A series (30000W) are appropriate for applications experiencing severe transient events or requiring enhanced margin. All maintain the 48V standoff voltage and -55°C to 175°C operating range.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All substitute parts listed are ROHS3 compliant. The Vishay and Microchip variants also carry REACH unaffected status, providing additional environmental compliance assurance.

Q: What is the significance of the voltage breakdown minimum specification?

A: The voltage breakdown minimum (50.49V for 3KP48-B, 53.3V to 53.6V for substitutes) ensures the device activates above the reverse standoff voltage. Substitute parts with slightly higher breakdown voltages (53.3V to 53.6V) remain within acceptable operating margins and do not compromise circuit protection.

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