P4SMA51C Equivalent & Substitute Parts

Part Overview

The P4SMA51C is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose voltage clamping applications. This component features a 43.6V reverse standoff voltage with a maximum clamping voltage of 73.61V at peak pulse current. The part is classified as obsolete, necessitating identification of active equivalent alternatives that maintain electrical and mechanical compatibility for continued system support and new designs.

Substiute Parts

P4SMA51C

Littelfuse Inc.In Stock: 700P4SMA51C Datasheet

Current PartRFQ

P4SMA51CA

Eaton - Electronics DivisionIn Stock: 5185P4SMA51CA Datasheet

DirectRFQ

P4SMA51CA

Eaton - Electronics DivisionIn Stock: 5185P4SMA51CA Datasheet

DirectRFQ

SMAJP4KE51CA-TP

Micro Commercial CoIn Stock: 751SMAJP4KE51CA-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the P4SMA51C is determined by strict equivalence across the following electrical and mechanical parameters:

• Reverse standoff voltage: 43.6V (required match)
• Peak pulse current rating: 5.8A (required match)
• Peak pulse power: 400W (required match)
• Bidirectional channels: 1 (required match)
• Package/case type: DO-214AC, SMA (required match)
• Mounting type: Surface Mount (required match)

Acceptable variations within substitute parts include clamping voltage (70.1V to 73.61V range), breakdown voltage minimum (46.08V to 48.5V range), and operating temperature range extensions. These variations remain within the functional envelope for TVS diode operation in the specified application category.

Parameter Comparison

Engineering Selection Recommendations

Both P4SMA51CA (Eaton) and SMAJP4KE51CA-TP (Micro Commercial Co) are active product alternatives to the obsolete P4SMA51C. Selection between these substitutes is based on the following criteria:

P4SMA51CA (Eaton - Electronics Division): This part maintains active product status with RoHS compliance certification. It is packaged in Tape & Reel format, suitable for automated assembly processes. The operating temperature range of -55°C to 150°C covers standard industrial applications. This substitute is designated for telecom applications.

SMAJP4KE51CA-TP (Micro Commercial Co): This part also maintains active product status with extended operating temperature range of -55°C to 175°C, providing thermal margin for high-temperature environments. It is supplied in bulk packaging. REACH status is unaffected, indicating no regulatory restrictions on use.

Both substitutes meet the core electrical requirements of the P4SMA51C with equivalent standoff voltage, peak pulse current, and power ratings. The selection between them depends on packaging requirements (Tape & Reel versus bulk), application temperature environment, and supply chain availability.

Frequently Asked Questions (FAQ)

Q: Can P4SMA51CA replace P4SMA51C in existing designs?

A: Yes. The P4SMA51CA maintains electrical equivalence across all critical parameters: 43.6V reverse standoff voltage, 5.8A peak pulse current, 400W peak pulse power, and identical DO-214AC (SMA) package configuration. The clamping voltage of 70.1V is within acceptable operating range for TVS diode applications.

Q: What is the difference between the two substitute parts?

A: Both P4SMA51CA and SMAJP4KE51CA-TP are electrically equivalent. Primary differences are packaging format (Tape & Reel versus bulk), operating temperature range (P4SMA51CA: -55°C to 150°C; SMAJP4KE51CA-TP: -55°C to 175°C), and application designation (telecom versus general purpose).

Q: Are there package compatibility concerns?

A: No. All three parts use the DO-214AC (SMA) surface mount package. PCB footprints and reflow soldering profiles are identical across all substitutes.

Q: Does the lower clamping voltage of the substitutes affect circuit protection?

A: The clamping voltage of 70.1V in both substitutes is lower than the original 73.61V. This provides equivalent or improved transient suppression performance, as lower clamping voltage reduces voltage stress on protected components.

Q: Are compliance certifications equivalent?

A: P4SMA51CA carries RoHS compliance. SMAJP4KE51CA-TP has REACH unaffected status. Both meet regulatory requirements for their respective application markets. Verify specific compliance requirements for your end application.