SA40 Transient Voltage Suppressor (TVS) Diode - Equivalent & Substitute Parts

Part Overview

The SA40 is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for general-purpose transient voltage protection applications. This component features a 40V reverse standoff voltage rating with a 67.73V maximum clamping voltage and 7.9A peak pulse current capability in a through-hole DO-204AC (DO-15) axial package. The SA40 is classified as obsolete, making identification of functionally equivalent active alternatives essential for new designs and component procurement.

Substiute Parts

SA40

Littelfuse Inc.In Stock: 847SA40 Datasheet

Current PartRFQ

SA40A

Taiwan Semiconductor CorporationIn Stock: 1177SA40A Datasheet

DirectRFQ

P5KE40A-TP

Micro Commercial CoIn Stock: 911P5KE40A-TP Datasheet

MFR RecommendedRFQ

SA40A-AP

Micro Commercial CoIn Stock: 826SA40A-AP Datasheet

MFR RecommendedRFQ

SA40A-BP

Micro Commercial CoIn Stock: 1167SA40A-BP Datasheet

MFR RecommendedRFQ

SA40A-TP

Micro Commercial CoIn Stock: 868SA40A-TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SA40 is determined by strict equivalence across the following critical parameters:

• Voltage Rating: Reverse standoff voltage of 40V and breakdown voltage minimum of 42.08V
• Clamping Voltage: Maximum clamping voltage at peak pulse current (Ipp) must not exceed 67.73V to ensure protection circuit integrity
• Peak Pulse Current: Minimum 7.9A capability at 10/1000µs pulse profile
• Power Dissipation: 500W peak pulse power rating
• Package Compatibility: DO-204AC (DO-15) axial through-hole configuration
• Device Type: Zener-type unidirectional TVS diode with single channel
• Temperature Range: Operating junction temperature range of -55°C to 175°C

All identified substitute parts maintain these electrical and mechanical specifications within the allowed tolerances for direct functional replacement.

Parameter Comparison

Engineering Selection Recommendations

All identified substitute parts are classified as active products with current manufacturing status, addressing the obsolescence of the original SA40. The substitute parts maintain functional equivalence across all critical electrical parameters within specified tolerances.

SA40A (Taiwan Semiconductor Corporation) is available in Tape & Reel packaging with ROHS3 compliance and REACH unaffected status, providing a direct active alternative with identical series designation.

P5KE40A-TP, SA40A-AP, SA40A-BP, and SA40A-TP (Micro Commercial Co) are all active products with ROHS3 compliance and REACH unaffected status. These parts are available in bulk packaging configurations. The P5KE40A-TP offers an extended lower operating temperature limit of -65°C compared to the standard -55°C specification of other alternatives.

All substitute parts maintain the DO-204AC (DO-15) axial through-hole package configuration, ensuring direct mechanical and electrical compatibility with existing circuit board layouts designed for the SA40.

Frequently Asked Questions (FAQ)

Q: Can SA40A substitute parts be used directly in place of the obsolete SA40?

A: Yes. All identified SA40A variants and P5KE40A-TP maintain the critical electrical parameters (40V reverse standoff, 64.5V clamping voltage, 7.8-8.1A peak pulse current, 500W power rating) and identical DO-204AC (DO-15) through-hole axial package configuration. The substitute parts are functionally equivalent for general-purpose transient voltage suppression applications.

Q: What is the difference between the various SA40A part numbers from Micro Commercial Co?

A: SA40A-AP, SA40A-BP, and SA40A-TP are all variants of the SA40A base product number from Micro Commercial Co. All three maintain identical electrical specifications (40V standoff, 44.4V breakdown minimum, 64.5V clamping, 7.9A peak pulse current) and operating temperature range (-55 to 175°C). The suffix designations indicate different packaging or distribution configurations (bulk packaging in all cases), but electrical performance is equivalent.

Q: How does the P5KE40A-TP differ from the SA40A variants?

A: The P5KE40A-TP from Micro Commercial Co maintains equivalent voltage ratings (40V standoff, 44.4V breakdown, 64.5V clamping) and power dissipation (500W). The primary difference is the extended lower operating temperature limit of -65°C compared to -55°C for SA40A variants. Peak pulse current is 7.8A versus 7.9A for SA40A parts. Both are compatible with the original SA40 circuit application.

Q: Are all substitute parts RoHS compliant?

A: SA40A (Taiwan Semiconductor), SA40A-AP, SA40A-BP, and SA40A-TP (Micro Commercial Co) are all ROHS3 compliant. RoHS compliance status is not specified for P5KE40A-TP in the provided data.

Q: What is the significance of the clamping voltage difference between SA40 (67.73V) and substitute parts (64.5V)?

A: The substitute parts exhibit lower maximum clamping voltage (64.5V versus 67.73V), which provides improved transient suppression performance by limiting voltage peaks to a lower threshold. This is within acceptable substitution parameters and does not compromise circuit protection.

Q: Can these parts be used in new designs or only as replacements for obsolete SA40 components?

A: All identified substitute parts are active products suitable for both new designs and obsolescence replacement applications. The active product status ensures long-term availability and manufacturing continuity.