P4SMA18A_D84Z Equivalent & Substitute Parts

Part Overview

The P4SMA18A_D84Z is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by onsemi, designed for general-purpose overvoltage protection in surface-mount applications. This component features a 15.3V reverse standoff voltage, 25.2V maximum clamping voltage, and 15.9A peak pulse current capability in a DO-214AC (SMA) package. The part is currently classified as obsolete, making identification of equivalent and substitute components essential for ongoing design support and production continuity.

Substiute Parts

P4SMA18A_D84Z

onsemiIn Stock: 759P4SMA18A_D84Z Datasheet

Current PartRFQ

P4SMA18A

Fairchild SemiconductorIn Stock: 165157P4SMA18A Datasheet

DirectRFQ

P4SMA18A-E3/61

Vishay General Semiconductor - Diodes DivisionIn Stock: 20802P4SMA18A-E3/61 Datasheet

DirectRFQ

P4SMA18A-M3/61

Vishay General Semiconductor - Diodes DivisionIn Stock: 867P4SMA18A-M3/61 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the P4SMA18A_D84Z is determined by strict equivalence across the following critical electrical and mechanical parameters:

• Voltage - Reverse Standoff (Typ): 15.3V
• Voltage - Breakdown (Min): 17.1V
• Voltage - Clamping (Max) @ Ipp: 25.2V (tolerance range 25.2V–25.5V acceptable)
• Current - Peak Pulse (10/1000µs): 15.9A (tolerance range 15.9A–16.1A acceptable)
• Power - Peak Pulse: 400W
• Operating Temperature Range: -65°C ~ 150°C (TJ)
• Package / Case: DO-214AC, SMA
• Mounting Type: Surface Mount
• Unidirectional Channels: 1
• Type: Zener

All substitute parts listed below meet these criteria within specified tolerances and maintain functional equivalence for general-purpose transient voltage suppression applications.

Parameter Comparison

Engineering Selection Recommendations

For applications currently using the P4SMA18A_D84Z, the following selection criteria apply:

Active Product Status Priority: P4SMA18A-E3/61 and P4SMA18A-M3/61 (both Vishay) are classified as active products, providing superior long-term availability and supply chain continuity compared to the obsolete onsemi original and Fairchild substitute.

Compliance Certification: All substitute parts carry ROHS3 compliance certification. The P4SMA18A (Fairchild) does not specify RoHS status and carries obsolete product classification, limiting its suitability for new designs or long-term production support.

Electrical Equivalence: P4SMA18A-E3/61 and P4SMA18A-M3/61 provide exact electrical parameter matching to the original P4SMA18A_D84Z across all critical specifications. The P4SMA18A (Fairchild) exhibits a marginal clamping voltage variance (25.5V vs. 25.2V) and peak pulse current variance (16.1A vs. 15.9A), remaining within acceptable tolerance for general-purpose applications but representing a secondary choice.

Packaging and Moisture Sensitivity: All substitute parts maintain DO-214AC (SMA) surface-mount packaging with MSL 1 (Unlimited) moisture sensitivity rating, ensuring direct PCB assembly compatibility without additional handling requirements.

Frequently Asked Questions (FAQ)

Q: Can P4SMA18A (Fairchild) be used as a direct replacement for P4SMA18A_D84Z?

A: Yes, P4SMA18A (Fairchild) meets all critical electrical parameters within acceptable tolerance. However, both the original and this substitute are classified as obsolete. For new designs or sustained production, Vishay alternatives are preferred due to active product status.

Q: What is the difference between P4SMA18A-E3/61 and P4SMA18A-M3/61?

A: Both parts are manufactured by Vishay and share identical electrical specifications, operating temperature range, and package type. The primary difference is packaging format: P4SMA18A-E3/61 and P4SMA18A-M3/61 are both supplied in Tape & Reel (TR) format. Selection between these variants depends on procurement quantity and assembly line requirements.

Q: Are all substitute parts compatible with existing PCB designs?

A: Yes. All substitute parts use the DO-214AC (SMA) surface-mount package, ensuring direct footprint compatibility with designs originally specified for the P4SMA18A_D84Z. No PCB layout modifications are required.

Q: What compliance certifications apply to substitute parts?

A: P4SMA18A-E3/61 and P4SMA18A-M3/61 are ROHS3 compliant. All parts carry REACH Unaffected status and EAR99 export classification. Moisture sensitivity level is MSL 1 (Unlimited) for all variants.

Q: Can clamping voltage variance (25.2V vs. 25.5V) affect circuit performance?

A: The 0.3V variance between P4SMA18A_D84Z (25.2V) and P4SMA18A (Fairchild, 25.5V) remains within standard TVS diode manufacturing tolerance and does not compromise general-purpose transient suppression functionality. Circuit design margins should accommodate this variance.

Q: Which substitute part offers the best long-term availability?

A: P4SMA18A-E3/61 and P4SMA18A-M3/61 (Vishay) are both active products with significantly higher inventory levels (20,700 and 807 units respectively) compared to obsolete alternatives, providing superior supply chain continuity for ongoing production requirements.