Equivalent & Substitute Parts for T107D2

Part Overview

The T107D2 is a sensitive gate SCR (Silicon Controlled Rectifier) rated for 400V off-state voltage and 4A RMS current, manufactured by Littelfuse Inc. in a TO-202 through-hole package. This part is classified as obsolete, making identification of active equivalent components essential for ongoing system support and new design implementations. The T107D2 remains in stock (826 pcs available), but its obsolete status necessitates evaluation of current production alternatives that maintain electrical and mechanical compatibility.

Substiute Parts

T107D2

Littelfuse Inc.In Stock: 871T107D2 Datasheet

Current PartRFQ

S4004VS2TP

Littelfuse Inc.In Stock: 2208S4004VS2TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the T107D2 is determined by strict equivalence across the following critical parameters:

• Voltage Rating (Off State): 400V minimum requirement
• Current Rating (RMS): 4A minimum requirement
• SCR Type: Sensitive Gate classification
• Gate Trigger Characteristics: Vgt ≤ 800 mV and Igt ≤ 500 µA
• On-State Performance: Vtm ≤ 2.5V, Ih ≤ 6 mA
• Operating Temperature: -40°C to 110°C range
• Compliance: ROHS3 Compliant status

The S4004VS2TP qualifies as a direct substitute based on matching all critical electrical parameters while offering improved performance characteristics and active product status. The primary difference is the package format (TO-251AA versus TO-202), which requires PCB layout modification but maintains electrical equivalence.

Parameter Comparison

Engineering Selection Recommendations

The S4004VS2TP is the manufacturer-recommended substitute for the T107D2. Selection is based on the following engineering criteria:

Electrical Equivalence: The S4004VS2TP maintains all critical voltage and current ratings required for direct functional replacement. Gate trigger parameters are equal or superior, ensuring reliable circuit operation.

Performance Enhancement: The substitute demonstrates improved on-state voltage characteristics (1.6V versus 2.5V) and higher non-repetitive surge current ratings (25A/30A versus 16A/20A), providing enhanced thermal performance and transient protection margins.

Product Status and Compliance: The S4004VS2TP is an active product with full ROHS3 compliance and REACH unaffected status, ensuring long-term availability and regulatory alignment. The T107D2 obsolete status creates supply chain risk for ongoing production.

Package Consideration: The transition from TO-202 to TO-251AA requires PCB footprint modification. This is a mechanical change only; no circuit redesign is necessary. The TO-251AA package offers improved thermal dissipation characteristics due to its larger lead frame design.

Frequently Asked Questions (FAQ)

Q: Can the S4004VS2TP be used as a direct pin-for-pin replacement for the T107D2?

A: No. While electrically equivalent, the S4004VS2TP uses the TO-251AA package versus the T107D2 TO-202 package. Pin assignments differ, requiring PCB layout modification. Consult the respective datasheets for pinout configuration.

Q: What are the key electrical differences between these parts?

A: The S4004VS2TP offers improved performance: lower on-state voltage (1.6V vs 2.5V), lower gate trigger current (200µA vs 500µA), and higher surge current ratings (25A/30A vs 16A/20A). All critical voltage and RMS current ratings remain equivalent.

Q: Is the S4004VS2TP suitable for applications currently using the T107D2?

A: Yes, provided the PCB layout is modified to accommodate the TO-251AA package. The electrical performance is equivalent or superior across all specified parameters. Verify gate drive circuit compatibility with the lower Igt specification.

Q: What is the availability status of these parts?

A: The T107D2 is obsolete with 826 pcs in current stock. The S4004VS2TP is an active product with 2112 pcs in stock, providing superior long-term availability.

Q: Are both parts RoHS compliant?

A: Yes. Both the T107D2 and S4004VS2TP are ROHS3 compliant. The S4004VS2TP additionally carries REACH unaffected status.

Q: What thermal considerations apply to the package change?

A: The TO-251AA package features a larger lead frame and improved thermal coupling compared to TO-202. This results in better heat dissipation characteristics, reducing junction temperature under equivalent load conditions.