SA85 Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SA85 is a unidirectional Zener-type transient voltage suppressor diode manufactured by Littelfuse Inc., designed for general-purpose overvoltage protection applications. The device features an 85V reverse standoff voltage with a 143.85V maximum clamping voltage and 3.7A peak pulse current capability in a through-hole DO-204AC (DO-15) axial package. The SA85 is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

SA85

Littelfuse Inc.In Stock: 836SA85 Datasheet

Current PartRFQ

SA85A

Taiwan Semiconductor CorporationIn Stock: 1219SA85A Datasheet

DirectRFQ

P6KE100A

Fairchild SemiconductorIn Stock: 18965P6KE100A Datasheet

MFR RecommendedRFQ

SA85A-AP

Micro Commercial CoIn Stock: 1004SA85A-AP Datasheet

MFR RecommendedRFQ

SA85A-BP

Micro Commercial CoIn Stock: 931SA85A-BP Datasheet

MFR RecommendedRFQ

SA85A-TP

Micro Commercial CoIn Stock: 1094SA85A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SA85 are qualified based on the following critical parameters that determine functional equivalence:

• Voltage - Reverse Standoff (Typ): 85V nominal rating
• Voltage - Clamping (Max) @ Ipp: Maximum 143.85V to 137V range
• Current - Peak Pulse (10/1000µs): 3.7A to 4.4A range
• Power - Peak Pulse: 500W to 600W range
• Operating Temperature Range: -55°C to 175°C (or -55°C to 150°C minimum)
• Mounting Type: Through Hole
• Package / Case: DO-204AC or DO-15 axial configuration
• Type: Zener diode, unidirectional (1 channel)

Substitutes are grouped into two categories: direct equivalents (SA85A variants) and functionally compatible alternatives (P6KE100A). Direct equivalents maintain identical standoff voltage and comparable electrical characteristics. The P6KE100A operates at a higher 100V standoff voltage but provides superior peak pulse current and power handling, suitable for applications requiring enhanced transient protection margins.

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalents (Preferred for SA85 Replacement):

The SA85A from Taiwan Semiconductor Corporation is the primary direct equivalent, maintaining identical 85V reverse standoff voltage with marginally improved clamping voltage (137V vs. 143.85V) and peak pulse current (3.8A vs. 3.7A). The SA85A is available in active production status with ROHS3 compliance and full temperature range support (-55°C to 175°C). Three packaging variants are available through Micro Commercial Co (SA85A-AP, SA85A-BP, SA85A-TP), all maintaining identical electrical specifications with bulk packaging options.

Alternative with Enhanced Performance (P6KE100A):

The P6KE100A from Fairchild Semiconductor operates at a higher 100V reverse standoff voltage, providing increased transient protection margin. This device delivers superior peak pulse current (4.4A) and power handling (600W vs. 500W), suitable for applications requiring enhanced overvoltage suppression capability. The operating temperature range is limited to -55°C to 150°C. Selection of P6KE100A requires circuit validation to confirm compatibility with the higher standoff voltage specification.

All substitute parts maintain through-hole mounting in DO-204AC or DO-15 axial packages, ensuring mechanical and electrical compatibility with existing PCB designs. All listed substitutes carry ROHS3 compliance and are in active production status.

Frequently Asked Questions (FAQ)

Q: Can SA85A variants (SA85A-AP, SA85A-BP, SA85A-TP) be used interchangeably?

A: Yes. All three variants maintain identical electrical specifications (85V standoff, 137V clamping, 3.7A peak pulse current, 500W power rating, -55°C to 175°C operating range) and package configuration (DO-15). The suffix designations indicate packaging format (Bulk) and supplier differentiation only. Selection depends on procurement availability and packaging requirements.

Q: What is the difference between SA85A and P6KE100A?

A: The primary difference is reverse standoff voltage: SA85A operates at 85V nominal, while P6KE100A operates at 100V nominal. The P6KE100A provides higher peak pulse current (4.4A vs. 3.8A) and greater power dissipation (600W vs. 500W). The P6KE100A has a reduced operating temperature maximum of 150°C versus 175°C for SA85A. Circuit validation is required before substituting P6KE100A for SA85A due to the higher standoff voltage.

Q: Are all substitute parts compatible with the original SA85 PCB footprint?

A: Yes. All substitute parts use through-hole mounting in DO-204AC or DO-15 axial packages, maintaining identical lead spacing and footprint compatibility with the original SA85 design.

Q: What compliance certifications apply to these substitute parts?

A: All listed substitute parts are ROHS3 compliant. SA85A and MCC variants (SA85A-AP, SA85A-BP, SA85A-TP) carry REACH Unaffected status. All parts are classified under ECCN EAR99 and HTSUS 8541.10.0080.

Q: Why is the SA85 listed as obsolete?

A: The SA85 is no longer in active production. Direct equivalents such as SA85A from Taiwan Semiconductor Corporation and MCC variants provide functional replacement with active production status and improved availability.