SA28C-B Equivalent & Substitute Parts

Part Overview

The SA28C-B is a transient voltage suppressor (TVS) diode manufactured by Littelfuse Inc., designed for telecom applications. This bidirectional zener diode operates with a 28V reverse standoff voltage and provides 500W peak pulse power protection in a through-hole DO-204AC (DO-15) package. The SA28C-B is classified as obsolete, necessitating identification of active equivalent parts to maintain design continuity and ensure ongoing component availability for new production and field replacements.

Substiute Parts

SA28C-B

Littelfuse Inc.In Stock: 941SA28C-B Datasheet

Current PartRFQ

SA28CA

Taiwan Semiconductor CorporationIn Stock: 1364SA28CA Datasheet

DirectRFQ

SA28CA-B

Littelfuse Inc.In Stock: 937SA28CA-B Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SA28C-B is determined by the following critical parameters:

Mandatory Matching Parameters:

• Voltage - Reverse Standoff (Typ): 28V
• Voltage - Breakdown (Min): 31.1V
• Package / Case: DO-204AC (DO-15), Axial
• Mounting Type: Through Hole
• Type: Zener
• Bidirectional Channels: 1
• Power - Peak Pulse: 500W

Allowable Variation Parameters:

• Voltage - Clamping (Max) @ Ipp: Substitutes may exceed the original 45.4V specification
• Current - Peak Pulse (10/1000µs): Substitutes may exceed the original 11.2A specification
• Operating Temperature Range: Substitutes must maintain or exceed the original -65°C ~ 175°C range
• Product Status: Active substitutes are preferred over obsolete parts

The identified substitute parts maintain all mandatory parameters while offering equal or superior performance characteristics in clamping voltage and peak pulse current ratings.

Parameter Comparison

Engineering Selection Recommendations

SA28CA-B (Littelfuse Inc.): This part is the direct active equivalent of the SA28C-B. It maintains identical electrical specifications including voltage ratings, peak pulse current, and operating temperature range. The SA28CA-B carries ROHS3 compliance and REACH unaffected status, meeting current regulatory requirements. This part is available in bulk packaging and is recommended as the primary replacement for the obsolete SA28C-B in telecom applications.

SA28CA (Taiwan Semiconductor Corporation): This part provides functional equivalence with identical reverse standoff and breakdown voltages. The SA28CA exhibits a higher clamping voltage (59V versus 45.4V) and marginally higher peak pulse current (11.5A versus 11.2A), representing superior transient suppression performance. The operating temperature range is -55°C ~ 175°C, which is narrower at the lower bound compared to the SA28C-B. The SA28CA is ROHS3 compliant and available in tape and reel packaging. This part is suitable for applications where the higher clamping voltage does not conflict with circuit design constraints.

Both substitute parts are active products with current regulatory compliance certifications, ensuring long-term availability and supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can SA28CA-B be used as a direct replacement for SA28C-B?

A: Yes. The SA28CA-B maintains identical electrical specifications across all critical parameters: 28V reverse standoff voltage, 31.1V minimum breakdown voltage, 45.4V maximum clamping voltage, 11.2A peak pulse current, and -65°C to 175°C operating temperature range. Both parts use the DO-204AC (DO-15) through-hole package. The SA28CA-B is the active equivalent of the obsolete SA28C-B.

Q: What is the difference between SA28CA-B and SA28CA?

A: Both parts share the same reverse standoff voltage (28V) and breakdown voltage (31.1V). The primary differences are: (1) SA28CA-B has a clamping voltage of 45.4V and SA28CA has 59V; (2) SA28CA-B has a peak pulse current of 11.2A and SA28CA has 11.5A; (3) SA28CA-B operates from -65°C to 175°C while SA28CA operates from -55°C to 175°C; (4) SA28CA-B is supplied in bulk packaging while SA28CA is supplied in tape and reel. Both are manufactured to the same DO-204AC package specification.

Q: Is the higher clamping voltage of SA28CA problematic?

A: The SA28CA's 59V clamping voltage is higher than the SA28C-B's 45.4V specification. This characteristic must be evaluated against circuit design requirements. A higher clamping voltage provides less aggressive transient suppression but may be acceptable depending on the protected circuit's voltage tolerance specifications.

Q: Are both substitute parts RoHS compliant?

A: Yes. Both SA28CA-B and SA28CA are ROHS3 compliant, meeting current environmental and regulatory standards. The original SA28C-B was RoHS compliant. All three parts are suitable for applications requiring RoHS certification.

Q: What packaging options are available?

A: SA28CA-B is supplied in bulk packaging, suitable for high-volume manufacturing and direct component placement. SA28CA is supplied in tape and reel (TR) packaging, optimized for automated assembly processes. Selection depends on production methodology and inventory management requirements.

Q: Can SA28CA be used in applications requiring the full -65°C lower temperature limit?

A: No. The SA28CA operates from -55°C to 175°C, which does not meet the -65°C lower temperature requirement of the original SA28C-B. If the application requires operation at -65°C, SA28CA-B is the appropriate substitute, as it maintains the full -65°C to 175°C operating range.