SA64ALFG Equivalent & Substitute Parts

Part Overview

The SA64ALFG is a transient voltage suppressor (TVS) diode manufactured by onsemi, designed for general-purpose overvoltage protection in through-hole axial configurations. This component operates with a 64V reverse standoff voltage and provides 103V maximum clamping voltage with 4.9A peak pulse current capability. The SA64ALFG is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and procurement continuity.

Substiute Parts

SA64ALFG

onsemiIn Stock: 729SA64ALFG Datasheet

Current PartRFQ

SA64A

Taiwan Semiconductor CorporationIn Stock: 3436SA64A Datasheet

DirectRFQ

1N8172

Microchip TechnologyIn Stock: 7271N8172 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SA64ALFG is determined by the following critical parameters:

• Voltage - Reverse Standoff: 64V (±tolerance acceptable within standard TVS specifications)
• Voltage - Clamping (Max) @ Ipp: 103V (maximum allowable clamp voltage)
• Mounting Type: Through Hole (mechanical compatibility)
• Package / Case: DO-204AC, DO-15, or Axial (physical form factor)
• Type: Zener (functional classification)
• Unidirectional Channels: 1 (circuit topology requirement)

Substitute parts must maintain these core electrical and mechanical parameters to ensure functional equivalence in circuit protection applications. Current-handling capacity and power dissipation may vary within acceptable operational limits for the intended application.

Parameter Comparison

Engineering Selection Recommendations

SA64A (Direct Substitute): This part is the primary equivalent for SA64ALFG replacement. It maintains identical voltage specifications (64V standoff, 103V clamp) and equivalent current handling (5A vs. 4.9A). The SA64A is manufactured by Taiwan Semiconductor Corporation and carries Active product status with extended operating temperature range (-55°C ~ 175°C). RoHS3 compliance is confirmed. Packaging is available in DO-204AC (DO-15) format, ensuring mechanical compatibility with original through-hole designs.

1N8172 (Similar Substitute): This Microchip Technology part meets the core voltage requirements (64V standoff, 103V clamp) and maintains through-hole axial packaging. However, the peak pulse current is significantly lower at 1.45A compared to 4.9A in the original design, and peak pulse power is reduced to 150W versus 500W. The 1N8172 is suitable only for applications where peak pulse current requirements do not exceed 1.45A. This part is Active and RoHS non-compliant.

Frequently Asked Questions (FAQ)

Q: Can SA64A directly replace SA64ALFG in existing designs? A: Yes. SA64A maintains identical reverse standoff voltage (64V), breakdown voltage (71.1V), and clamping voltage (103V). Peak pulse current is slightly higher (5A vs. 4.9A), and operating temperature range is extended. Physical packaging in DO-204AC format is compatible with through-hole axial mounting.

Q: What are the limitations of using 1N8172 as a substitute? A: The 1N8172 meets voltage specifications but has reduced current-handling capacity (1.45A peak pulse vs. 4.9A) and lower power dissipation (150W vs. 500W). Use this part only in applications where peak pulse current does not exceed 1.45A. RoHS non-compliance may be a consideration for certain regulatory environments.

Q: Are there packaging differences between substitute parts? A: SA64A is available in DO-204AC (DO-15) axial format, matching the original SA64ALFG package. The 1N8172 is supplied in axial format only. Both maintain through-hole mounting compatibility.

Q: How do operating temperature ranges affect substitution? A: SA64ALFG operates from -55°C to 150°C. Both SA64A and 1N8172 extend the upper limit to 175°C, providing improved thermal margin. This does not restrict substitution; extended range is beneficial for most applications.

Q: What compliance certifications should be verified for procurement? A: SA64A is RoHS3 compliant. The 1N8172 is RoHS non-compliant. Both parts are REACH unaffected and classified as EAR99 for export control purposes.