T106D2 Thyristor SCR 400V 4A Equivalent & Substitute Parts

Part Overview

The T106D2 is a sensitive gate SCR (silicon-controlled rectifier) rated for 400V off-state voltage and 4A RMS on-state current in a TO-202 through-hole package. This component is classified as obsolete, making equivalent substitutes necessary for new designs and production continuity. The T106D2 remains available in inventory (1417 pcs), but active alternatives with improved electrical performance characteristics are recommended for ongoing applications.

Substiute Parts

T106D2

Littelfuse Inc.In Stock: 1439T106D2 Datasheet

Current PartRFQ

S4004VS2TP

Littelfuse Inc.In Stock: 2208S4004VS2TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The S4004VS2TP qualifies as a direct substitute for the T106D2 based on the following critical parameters:

• Voltage Rating (Off State): Both parts maintain 400V off-state voltage, ensuring compatibility in the same circuit voltage class
• Gate Trigger Characteristics: Identical Vgt (800 mV max) and Igt (200 µA max) specifications allow the substitute to function with existing gate drive circuits
• On-State Current Rating: Both rated for 4A RMS, supporting equivalent load handling capacity
• Operating Temperature Range: Identical -40°C to 110°C range ensures thermal compatibility
• SCR Type: Both are sensitive gate SCRs, maintaining the same gate sensitivity classification
• Mounting Type: Both are through-hole components, compatible with existing PCB layouts

The S4004VS2TP differs in package form factor (TO-251AA vs. TO-202) and exhibits improved on-state voltage performance (1.6V vs. 2.2V max), representing a performance upgrade while maintaining functional equivalence.

Parameter Comparison

Engineering Selection Recommendations

The S4004VS2TP is the recommended substitute for the T106D2 based on the following factors:

• Product Status: The S4004VS2TP is active and in production, ensuring long-term availability and supply chain continuity. The T106D2 is obsolete, limiting future procurement options.
• Regulatory Compliance: Both parts are ROHS3 compliant. The S4004VS2TP additionally carries REACH Unaffected status, providing broader regulatory coverage for international applications.
• Electrical Equivalence: All critical electrical parameters (voltage rating, gate trigger levels, on-state current) are identical or superior, ensuring functional compatibility without circuit redesign.
• Performance Improvement: The S4004VS2TP exhibits lower on-state voltage (1.6V vs. 2.2V), reducing power dissipation and improving thermal performance in the same application.
• Package Consideration: The TO-251AA package requires PCB layout modification compared to the TO-202 form factor. Mechanical compatibility must be verified for existing designs.

Frequently Asked Questions (FAQ)

Q: Can the S4004VS2TP directly replace the T106D2 without circuit modification?

A: The S4004VS2TP is electrically equivalent and will function in circuits designed for the T106D2. However, the package form factor differs (TO-251AA vs. TO-202), requiring PCB layout changes. Gate drive circuits require no modification due to identical Vgt and Igt specifications.

Q: What is the primary advantage of substituting to the S4004VS2TP?

A: The S4004VS2TP offers lower on-state voltage (1.6V vs. 2.2V maximum), reducing power dissipation by approximately 27% at rated current. Additionally, active product status ensures ongoing availability and supply security.

Q: Are there any electrical performance differences that affect circuit operation?

A: The hold current (Ih) is slightly higher in the S4004VS2TP (6 mA vs. 5 mA), which is within acceptable tolerance for sensitive gate SCR applications. The lower on-state voltage represents an improvement that reduces thermal stress.

Q: What packaging considerations apply when switching from T106D2 to S4004VS2TP?

A: The T106D2 uses TO-202 Short Tab packaging, while the S4004VS2TP uses TO-251-3 (IPak) packaging. These packages have different lead configurations and footprints. PCB redesign is necessary to accommodate the new package geometry.

Q: Are both parts compliant with current regulatory standards?

A: Yes. Both the T106D2 and S4004VS2TP are ROHS3 compliant. The S4004VS2TP additionally carries REACH Unaffected status, providing compliance for applications requiring broader environmental and safety certifications.

Q: What is the voltage rating equivalence between these parts?

A: Both parts are rated for 400V off-state voltage and share identical gate trigger voltage specifications (800 mV maximum). They are fully equivalent for voltage class applications.