Equivalent & Substitute Parts for 3KP22-B TVS Diode

Part Overview

The 3KP22-B is a unidirectional transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection applications. This component features a 22V reverse standoff voltage, 37.28V maximum clamping voltage, and 84.5A peak pulse current capability in a through-hole P600 axial package. The product is currently obsolete, making equivalent and substitute parts necessary for ongoing system maintenance and new designs requiring similar protection characteristics.

Substiute Parts

3KP22-B

Littelfuse Inc.In Stock: 12093KP22-B Datasheet

Current PartRFQ

5KP22A-B

LittelfuseIn Stock: 11255KP22A-B Datasheet

DirectRFQ

15KPA22AE3/TR13

Microchip TechnologyIn Stock: 115615KPA22AE3/TR13 Datasheet

MFR RecommendedRFQ

5KP22A-E3/54

Vishay General Semiconductor - Diodes DivisionIn Stock: 29695KP22A-E3/54 Datasheet

MFR RecommendedRFQ

5KP22A-E3/73

Vishay General Semiconductor - Diodes DivisionIn Stock: 7775KP22A-E3/73 Datasheet

MFR RecommendedRFQ

5KP22AHE3/54

Vishay General Semiconductor - Diodes DivisionIn Stock: 7755KP22AHE3/54 Datasheet

MFR RecommendedRFQ

5KP22AHE3/73

Vishay General Semiconductor - Diodes DivisionIn Stock: 11455KP22AHE3/73 Datasheet

MFR RecommendedRFQ

BZW50-22

STMicroelectronicsIn Stock: 1173BZW50-22 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3KP22-B is determined by the following critical parameters:

• Voltage - Reverse Standoff (Typ): Must be 22V to maintain circuit protection threshold
• Unidirectional Channels: Must remain 1 channel
• Mounting Type: Must be Through Hole for PCB compatibility
• Package / Case: Must be P600 Axial to fit existing footprints
• Operating Temperature Range: Must support -55°C ~ 175°C (TJ)
• Type: Must be Zener diode technology
• RoHS Status: Must maintain ROHS3 compliance

Substitute parts are grouped into two categories based on power dissipation capability and peak pulse current handling:

Category A (5kW Power Rating): Parts with 5000W peak pulse power and higher peak pulse current (141A–143.7A), providing enhanced protection margin.

Category B (15kW Power Rating): Parts with 15000W peak pulse power and significantly higher peak pulse current (407A), suitable for high-energy transient environments.

All substitute parts maintain the same 22V reverse standoff voltage, P600 axial package, through-hole mounting, and operating temperature range as the original 3KP22-B.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (5kW Category):

The 5KP22A-B, 5KP22A-E3/54, 5KP22A-E3/73, and 5KP22AHE3/54/73 are direct functional replacements with identical 22V reverse standoff voltage and P600 axial package. These parts provide 67–69% higher peak pulse current (141–143.7A versus 84.5A) and increased power dissipation (5000W versus 3000W), delivering enhanced protection margin for the same circuit topology. All maintain ROHS3 compliance and -55°C to 175°C operating temperature range.

Automotive-Grade Alternatives:

The 5KP22AHE3/54 and 5KP22AHE3/73 are qualified to AEC-Q101 automotive standards and carry Automotive grade designation. These are suitable for applications requiring automotive-level reliability and traceability.

High-Power Alternative (15kW Category):

The 15KPA22AE3/TR13 from Microchip Technology provides 407A peak pulse current and 15000W power dissipation, appropriate for high-energy transient suppression in industrial or power distribution applications. This part maintains 22V reverse standoff voltage and P600 axial package compatibility.

Package Consideration:

The BZW50-22 from STMicroelectronics uses an R-6 axial package instead of P600. While electrically compatible at the 22V standoff level, the different package footprint requires PCB layout modification. This part exhibits higher clamping voltage (51V) and significantly higher peak pulse current (1177A), making it suitable only for applications where package change is acceptable and higher clamping voltage is tolerable.

Frequently Asked Questions (FAQ)

Q: Can I use any of these substitute parts as a direct drop-in replacement for the 3KP22-B?

A: Yes, all substitute parts except BZW50-22 are direct drop-in replacements. They share identical P600 axial package, 22V reverse standoff voltage, through-hole mounting, and operating temperature range. The BZW50-22 requires PCB layout modification due to its R-6 package.

Q: What is the difference between the 5kW and 15kW rated parts?

A: The 5kW parts (5KP22A series) handle 141–143.7A peak pulse current and dissipate 5000W maximum. The 15kW part (15KPA22AE3/TR13) handles 407A peak pulse current and dissipates 15000W maximum. Selection depends on the magnitude and frequency of transient events in your application.

Q: Are the automotive-grade parts (5KP22AHE3/54 and 5KP22AHE3/73) required for non-automotive applications?

A: No. Automotive-grade parts are specified only when AEC-Q101 qualification and automotive traceability are required. Standard-grade parts (5KP22A-B, 5KP22A-E3/54, 5KP22A-E3/73) are suitable for general-purpose applications.

Q: Why does the BZW50-22 have a higher clamping voltage (51V) than the original 3KP22-B (37.28V)?

A: The BZW50-22 is designed for different application requirements. The higher clamping voltage may not be suitable for circuits sensitive to voltage overshoot. Use this part only if your circuit design accommodates the higher clamping voltage.

Q: What does the packaging designation (Bulk, Cut Tape, Tape & Reel) mean?

A: Packaging designation indicates the form in which parts are supplied. Bulk is loose parts, Cut Tape (CT) is parts on carrier tape cut to length, and Tape & Reel (TR) is continuous tape on a reel. All are electrically identical; selection depends on your procurement and assembly process.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All substitute parts listed maintain ROHS3 compliance, matching the original 3KP22-B specification.

Q: Can I use the BZW50-22 if my PCB already has the P600 footprint?

A: No. The BZW50-22 uses an R-6 axial package, which has different lead spacing and diameter. PCB layout modification is required. Verify mechanical compatibility before substitution.