P4SMA51 Equivalent & Substitute Parts Reference

Part Overview

The P4SMA51 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient voltage protection in surface-mount applications. This component features a 43.6V reverse standoff voltage with a 73.61V maximum clamping voltage and 5.8A peak pulse current capability in a DO-214AC (SMA) package.

The P4SMA51 is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. Active alternatives with compatible electrical and mechanical specifications are available from multiple manufacturers.

Substiute Parts

P4SMA51

Littelfuse Inc.In Stock: 1164P4SMA51 Datasheet

Current PartRFQ

P4SMA51A

Eaton - Electronics DivisionIn Stock: 66763P4SMA51A Datasheet

MFR RecommendedRFQ

P4SMA51A

Eaton - Electronics DivisionIn Stock: 66763P4SMA51A Datasheet

MFR RecommendedRFQ

SMAJP4KE51A-TP

Micro Commercial CoIn Stock: 1106SMAJP4KE51A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the P4SMA51 is determined by strict equivalence across the following critical parameters:

• Voltage - Reverse Standoff (Typ): 43.6V
• Voltage - Clamping (Max) @ Ipp: Must remain within acceptable operating margins
• Current - Peak Pulse (10/1000µs): 5.8A
• Power - Peak Pulse: 400W
• Package / Case: DO-214AC, SMA (surface-mount compatibility)
• Mounting Type: Surface Mount
• Type: Zener, Unidirectional (1 channel)

The identified substitute parts P4SMA51A (Eaton - Electronics Division) and SMAJP4KE51A-TP (Micro Commercial Co) maintain electrical equivalence across these parameters while offering active product status and improved availability compared to the obsolete P4SMA51.

Parameter Comparison

Engineering Selection Recommendations

Both P4SMA51A and SMAJP4KE51A-TP are qualified substitutes for the obsolete P4SMA51 based on electrical parameter equivalence and active product status.

P4SMA51A (Eaton - Electronics Division) is the manufacturer-recommended substitute, maintaining identical reverse standoff voltage and peak pulse specifications. This part carries RoHS compliance certification and is available in Tape & Reel packaging with high inventory levels (66,655 pcs), supporting production volume requirements.

SMAJP4KE51A-TP (Micro Commercial Co) provides an alternative with extended operating temperature range (-55 to 175°C) compared to the original specification (-65 to 150°C). This part is available in Bulk packaging with active status and adequate inventory (1,079 pcs). The extended upper temperature rating may provide additional thermal margin in certain applications.

Both substitutes maintain the DO-214AC (SMA) package footprint and surface-mount compatibility required for direct board-level replacement.

Frequently Asked Questions (FAQ)

Q: Can P4SMA51A be used as a direct replacement for P4SMA51?

A: Yes. P4SMA51A maintains identical reverse standoff voltage (43.6V), peak pulse current (5.8A), and power dissipation (400W) specifications. The package and mounting type are identical (DO-214AC, SMA, surface mount). The clamping voltage is slightly lower (70.1V vs. 73.61V), which remains within acceptable operating margins for transient suppression applications.

Q: What is the difference between P4SMA51A and SMAJP4KE51A-TP?

A: Both parts maintain equivalent electrical specifications for reverse standoff voltage, peak pulse current, and power dissipation. The primary differences are manufacturer (Eaton vs. Micro Commercial Co), packaging format (Tape & Reel vs. Bulk), and operating temperature range (SMAJP4KE51A-TP extends to 175°C maximum junction temperature). Electrical performance in the specified operating range is equivalent.

Q: Are all three parts pin-compatible?

A: Yes. All three parts use the DO-214AC (SMA) package with identical pinout and footprint, enabling direct board-level substitution without layout modifications.

Q: Which substitute should be selected for new designs?

A: Selection should be based on procurement requirements and application constraints. P4SMA51A is the manufacturer-recommended option with established supply chain availability. SMAJP4KE51A-TP is suitable for applications requiring extended temperature operation or alternative sourcing.

Q: Do the substitute parts meet the same compliance standards?

A: P4SMA51A carries RoHS compliance certification. SMAJP4KE51A-TP is REACH Unaffected. Both parts maintain EAR99 export classification and identical HTSUS codes (8541.10.0080) as the original P4SMA51.