SA90-B Equivalent & Substitute Parts

Part Overview

The SA90-B is a unidirectional Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for telecom applications. This component provides transient voltage protection with a 90V reverse standoff voltage and 146V maximum clamping voltage at peak pulse current. The SA90-B is classified as obsolete, necessitating identification of equivalent substitute components that maintain electrical and mechanical compatibility for continued system support and new design implementations.

Substiute Parts

SA90-B

Littelfuse Inc.In Stock: 781SA90-B Datasheet

Current PartRFQ

SA90A

Taiwan Semiconductor CorporationIn Stock: 953SA90A Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SA90-B is determined by strict equivalence across the following critical electrical and mechanical parameters:

Electrical Parameters (Must Match):

• Voltage - Reverse Standoff (Typ): 90V
• Voltage - Breakdown (Min): 100V
• Voltage - Clamping (Max) @ Ipp: 146V
• Current - Peak Pulse (10/1000µs): 3.5A
• Power - Peak Pulse: 500W
• Unidirectional Channels: 1
• Type: Zener

Mechanical Parameters (Must Match):

• Mounting Type: Through Hole
• Package / Case: DO-204AC (DO-15)

The SA90A, manufactured by Taiwan Semiconductor Corporation, satisfies all electrical and mechanical equivalence criteria and is classified as an active product with current availability.

Parameter Comparison

Engineering Selection Recommendations

The SA90A is a direct electrical and mechanical equivalent to the SA90-B. Selection of the SA90A is supported by the following factors:

Product Status: The SA90A maintains active product status with current manufacturing and availability, whereas the SA90-B is obsolete. This ensures long-term supply chain continuity and access to technical support.

Compliance Certifications: Both components are RoHS compliant. The SA90A carries ROHS3 compliance certification, representing current regulatory alignment. Both components are classified as REACH Unaffected and carry identical ECCN and HTSUS classifications.

Electrical Equivalence: All critical electrical parameters—reverse standoff voltage, breakdown voltage, clamping voltage, peak pulse current, and peak pulse power—are identical between the two components.

Mechanical Compatibility: Both components utilize identical through-hole mounting and DO-204AC (DO-15) axial package configuration, ensuring direct board-level compatibility without layout modifications.

Operating Temperature Consideration: The SA90A operates across -55°C to 175°C, compared to the SA90-B range of -65°C to 175°C. The SA90A minimum operating temperature is 10°C higher. Applications requiring operation below -55°C require evaluation against specific system requirements.

Frequently Asked Questions (FAQ)

Q: Can the SA90A directly replace the SA90-B in existing designs?

A: Yes. The SA90A is electrically and mechanically equivalent to the SA90-B across all specified parameters. Direct substitution is supported without circuit modifications or board redesign. The identical DO-204AC (DO-15) package and through-hole mounting configuration enable direct board-level replacement.

Q: What is the significance of the operating temperature range difference?

A: The SA90-B operates from -65°C to 175°C, while the SA90A operates from -55°C to 175°C. The SA90A has a 10°C higher minimum operating temperature. Applications requiring operation below -55°C must evaluate whether this limitation affects system performance. Applications operating within -55°C to 175°C are unaffected.

Q: Are there packaging differences between SA90-B and SA90A?

A: Both components are supplied in DO-204AC (DO-15) axial through-hole packages. The SA90-B is supplied in standard packaging, while the SA90A is supplied in Tape & Reel (TR) format. This packaging difference does not affect electrical performance or board-level compatibility. Tape & Reel packaging is standard for active production components and provides handling and assembly advantages.

Q: What compliance certifications apply to the SA90A?

A: The SA90A is ROHS3 compliant, RoHS compliant, and REACH Unaffected. Both the SA90-B and SA90A carry identical ECCN (EAR99) and HTSUS (8541.10.0080) classifications, ensuring regulatory equivalence for export and import purposes.

Q: Why is the SA90-B classified as obsolete?

A: The SA90-B is no longer in active production. The SA90A represents the current active equivalent from Taiwan Semiconductor Corporation. Obsolescence classification indicates that new inventory production has ceased, though existing stock may remain available. The SA90A ensures access to actively manufactured equivalent components.

Q: Are the electrical characteristics identical between SA90-B and SA90A?

A: Yes. Both components share identical specifications for voltage - reverse standoff (90V), voltage - breakdown (100V), voltage - clamping (146V), current - peak pulse (3.5A), and power - peak pulse (500W). Both are unidirectional Zener-type TVS diodes with single channels.