SR05-02CTG Equivalent & Substitute Parts

Part Overview

The SR05-02CTG is a Transient Voltage Suppressor (TVS) diode manufactured by Littelfuse Inc., designed for power line protection in Ethernet applications. This steering TVS diode features a 5V reverse standoff voltage with an 18V clamping voltage and 25A peak pulse current rating in a surface mount SOT-143 package. The product is currently obsolete, making identification of equivalent substitute parts essential for ongoing design support and component procurement.

Substiute Parts

SR05-02CTG

Littelfuse Inc.In Stock: 15435SR05-02CTG Datasheet

Current PartRFQ

CD143A-SR05

Bourns Inc.In Stock: 50934CD143A-SR05 Datasheet

MFR RecommendedRFQ

SR05.TCT

Semtech CorporationIn Stock: 128803SR05.TCT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SR05-02CTG are qualified based on the following critical parameters that define functional equivalence:

• Voltage - Reverse Standoff: 5V (Max)
• Voltage - Breakdown (Min): 6V
• Type: Steering (Rail to Rail)
• Unidirectional Channels: 2
• Package / Case: SOT-143
• Mounting Type: Surface Mount
• Power Line Protection: Yes
• RoHS Status: ROHS3 Compliant

The identified substitute parts maintain these core electrical and mechanical specifications, ensuring direct functional replacement in Ethernet protection applications. Variations in clamping voltage (18V to 20V), peak pulse current (25A to 30A), and peak pulse power (450W to 500W) remain within acceptable operating margins for this product category.

Parameter Comparison

Engineering Selection Recommendations

Both CD143A-SR05 (Bourns Inc.) and SR05.TCT (Semtech Corporation) are active product alternatives to the obsolete SR05-02CTG. Selection between these substitutes should be based on the following factors:

CD143A-SR05 provides enhanced specifications with 30A peak pulse current and 500W peak pulse power, offering increased transient protection margin. This part is suitable for applications requiring maximum protection headroom.

SR05.TCT maintains the original 25A peak pulse current specification while providing 500W peak pulse power and active product status. This part aligns most closely with the electrical performance envelope of the original SR05-02CTG.

Both substitutes maintain ROHS3 compliance, MSL Level 1 rating, and identical reverse standoff and breakdown voltage specifications. Operating temperature ranges exceed the original specification, providing extended thermal performance. All parts are qualified for Ethernet power line protection applications and are available in active production status.

Frequently Asked Questions (FAQ)

Q: Can CD143A-SR05 and SR05.TCT be used interchangeably with SR05-02CTG?

A: Both parts meet the core substitution criteria: identical reverse standoff voltage (5V Max), breakdown voltage (6V Min), steering TVS type with 2 unidirectional channels, SOT-143 package, and surface mount configuration. Functional replacement is supported in Ethernet protection circuits.

Q: What is the significance of the clamping voltage difference between 18V and 20V?

A: The SR05-02CTG specifies 18V maximum clamping voltage, while both substitutes specify 20V. This 2V increase represents a higher transient voltage at peak pulse current and is within acceptable operating margins for this product category. Circuit design validation should confirm compatibility with protected component voltage ratings.

Q: Are there package compatibility considerations?

A: All parts use SOT-143 as the supplier device package. The SR05-02CTG is specified as SOT-143R, while substitutes are specified as TO-253-4 and TO-253AA. These designations refer to the same physical footprint and pin configuration, ensuring PCB layout compatibility.

Q: Why is product status relevant for substitution?

A: The SR05-02CTG is obsolete, meaning Littelfuse Inc. no longer manufactures or supports this part. CD143A-SR05 and SR05.TCT are active products with ongoing manufacturing and technical support, ensuring long-term component availability and supply chain continuity.

Q: Do the substitutes maintain compliance certifications?

A: Both CD143A-SR05 and SR05.TCT are ROHS3 compliant with MSL Level 1 rating and EAR99 export classification, matching the original part's compliance profile. REACH status is unaffected for both substitutes.