3KP45CA-B Equivalent & Substitute Parts

Part Overview

The 3KP45CA-B is a Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose voltage transient protection in through-hole applications. This component features a 45V reverse standoff voltage with a 72.7V maximum clamping voltage and 41.3A peak pulse current capability. The part is currently classified as obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations.

Substiute Parts

3KP45CA-B

Littelfuse Inc.In Stock: 9873KP45CA-B Datasheet

Current PartRFQ

5KP45CA-B

LittelfuseIn Stock: 8775KP45CA-B Datasheet

DirectRFQ

3KP45CA-TP

Micro Commercial CoIn Stock: 9553KP45CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 3KP45CA-B is determined by strict electrical and mechanical compatibility criteria. The following parameters must remain constant or within acceptable ranges for direct substitution:

• Voltage - Reverse Standoff: 45V (nominal)
• Voltage - Breakdown (Min): 50V
• Voltage - Clamping (Max) @ Ipp: 72.7V
• Operating Temperature Range: -55°C ~ 175°C (TJ)
• Mounting Type: Through Hole
• Bidirectional Channels: 1
• Type: Zener

The following parameters may vary within functional limits:

• Current - Peak Pulse (10/1000µs): Must be equal to or greater than 41.3A
• Power - Peak Pulse: Must be equal to or greater than 3000W
• Package / Case: Alternative axial through-hole packages acceptable if mechanical fit permits
• Manufacturer: Alternative qualified manufacturers acceptable

Parameter Comparison

Engineering Selection Recommendations

5KP45CA-B (Direct Substitute - Preferred)

The 5KP45CA-B is the primary substitute for the obsolete 3KP45CA-B. This component maintains identical voltage specifications (45V standoff, 50V breakdown, 72.7V clamping) and operating temperature range while providing enhanced current and power handling capabilities (70.2A peak pulse current, 5000W peak pulse power versus 41.3A and 3000W respectively). The 5KP45CA-B is manufactured by Littelfuse Inc. in active production status, ensuring long-term availability. Both components use identical P600 axial packaging, permitting direct mechanical substitution. ROHS3 compliance is maintained. The increased power rating provides design margin without introducing incompatibility.

3KP45CA-TP (Manufacturer-Recommended Alternative)

The 3KP45CA-TP, manufactured by Micro Commercial Co, provides electrical equivalence to the original 3KP45CA-B with identical voltage and current specifications (45V standoff, 72.7V clamping, 41.3A peak pulse, 3000W power). This component is in active production status. The primary distinction is the package variant: R-6 axial versus P600 axial. Mechanical fit verification is required before selection, as the R-6 package may have different lead spacing or dimensions compared to the original P600 package. REACH compliance is confirmed; RoHS status is not specified in available documentation.

Frequently Asked Questions (FAQ)

Q: Can the 5KP45CA-B be used as a direct replacement for the 3KP45CA-B?

A: Yes. The 5KP45CA-B maintains all critical voltage parameters (45V standoff, 72.7V clamping) and operating temperature specifications. The increased current rating (70.2A versus 41.3A) and power rating (5000W versus 3000W) provide enhanced transient suppression capability without introducing electrical incompatibility. Identical P600 axial packaging permits direct mechanical substitution.

Q: What is the difference between the 5KP45CA-B and 3KP45CA-TP?

A: Both components provide identical voltage and current specifications. The 5KP45CA-B offers higher power dissipation (5000W versus 3000W) and uses P600 packaging. The 3KP45CA-TP uses R-6 packaging and matches the original 3000W power rating. Package selection depends on mechanical fit requirements and PCB layout constraints.

Q: Are there any compliance differences between substitute options?

A: The 5KP45CA-B and original 3KP45CA-B are both ROHS3 compliant. The 3KP45CA-TP confirms REACH compliance; RoHS status is not documented. Verify compliance requirements against your specific application standards before final selection.

Q: Does the higher power rating of the 5KP45CA-B affect circuit performance?

A: No. The 5KP45CA-B maintains identical voltage clamping characteristics. The higher power rating reflects improved thermal dissipation capability and does not alter the transient suppression voltage profile. This provides additional design margin for transient events.

Q: What packaging considerations apply to the 3KP45CA-TP?

A: The 3KP45CA-TP uses R-6 axial packaging instead of the original P600. Verify lead spacing, diameter, and length compatibility with existing PCB footprints and through-hole dimensions before implementation.