SA40C-B Equivalent & Substitute Parts

Part Overview

The SA40C-B is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for telecom applications. This bidirectional Zener diode operates in the DO-204AC (DO-15) axial package and provides 40V reverse standoff voltage with 64.5V maximum clamping voltage at peak pulse current. The SA40C-B is classified as obsolete, necessitating identification of active equivalent parts to maintain design continuity and ensure ongoing component availability for production and field service applications.

Substiute Parts

SA40C-B

Littelfuse Inc.In Stock: 860SA40C-B Datasheet

Current PartRFQ

SA40CA

Taiwan Semiconductor CorporationIn Stock: 1417SA40CA Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SA40C-B is based on electrical and mechanical parameter equivalence within the TVS diode category. The substitute part SA40CA maintains identical specifications across all critical parameters that determine functional compatibility: reverse standoff voltage (40V), breakdown voltage (44.4V minimum), clamping voltage (64.5V maximum), power dissipation (500W peak pulse), operating temperature range, package type (DO-204AC), and mounting configuration (through-hole axial).

The SA40CA differs from the SA40C-B in the following aspects: peak pulse current (8.1A versus 7.9A), manufacturer (Taiwan Semiconductor Corporation versus Littelfuse Inc.), product status (active versus obsolete), and packaging format (tape & reel versus bulk). These differences do not affect electrical substitution compatibility, as the SA40CA peak pulse current exceeds the original specification, and the through-hole axial package remains identical.

Parameter Comparison

Engineering Selection Recommendations

The SA40CA is a direct electrical substitute for the SA40C-B in applications requiring a 40V reverse standoff TVS diode with 64.5V clamping voltage in the DO-204AC through-hole axial package. The SA40CA is manufactured by Taiwan Semiconductor Corporation and maintains active product status, ensuring long-term availability and supply chain continuity.

The SA40CA exhibits superior peak pulse current capability (8.1A) compared to the SA40C-B (7.9A), providing additional margin in transient suppression performance. Both parts comply with RoHS regulations and feature identical moisture sensitivity classification (MSL 1).

The operating temperature range of the SA40CA (-55°C to 175°C) is narrower than the SA40C-B (-65°C to 175°C) at the lower temperature extreme. Applications requiring operation below -55°C require evaluation against specific system requirements.

Both parts carry identical ECCN (EAR99) and HTSUS (8541.10.0080) classifications, supporting consistent regulatory and trade compliance documentation.

Frequently Asked Questions (FAQ)

Q: Can the SA40CA be used as a direct replacement for the SA40C-B in existing designs?

A: Yes. The SA40CA provides electrical equivalence across all critical TVS diode parameters: reverse standoff voltage, breakdown voltage, clamping voltage, power dissipation, and package configuration. The through-hole axial DO-204AC package is identical, enabling direct PCB mounting compatibility.

Q: What is the significance of the higher peak pulse current in the SA40CA (8.1A versus 7.9A)?

A: The SA40CA peak pulse current exceeds the SA40C-B specification, indicating enhanced transient suppression capability. This provides additional design margin and does not create compatibility issues in applications designed for the SA40C-B.

Q: Does the narrower operating temperature range of the SA40CA (-55°C to 175°C versus -65°C to 175°C) affect substitution?

A: The SA40CA operating temperature range is narrower at the lower extreme. Applications requiring operation below -55°C must confirm compatibility with system thermal requirements. Applications operating within -55°C to 175°C range experience no limitation.

Q: Are there packaging differences between the SA40C-B and SA40CA?

A: Both parts use the DO-204AC (DO-15) axial through-hole package. The SA40C-B is supplied in bulk packaging, while the SA40CA is supplied in tape & reel format. This difference affects procurement and assembly processes but does not alter electrical or mechanical compatibility.

Q: What is the compliance status of both parts?

A: The SA40C-B is RoHS Compliant. The SA40CA is ROHS3 Compliant, representing a more recent regulatory standard. Both parts are MSL 1 (Unlimited moisture sensitivity), eliminating moisture-related handling constraints. The SA40CA includes REACH Unaffected status.

Q: Why is the SA40C-B classified as obsolete?

A: The SA40C-B is designated obsolete by Littelfuse Inc., indicating discontinued manufacturing and limited future availability. The SA40CA, as an active product from Taiwan Semiconductor Corporation, provides ongoing supply assurance for new production and field service requirements.