DC34-TP Equivalent & Substitute Parts

Part Overview

The DC34-TP is a bidirectional DIAC thyristor in DO-35G axial package, rated for 30–38V breakover voltage with 2A peak output current. Manufactured by Micro Commercial Co, this component is classified as obsolete, making equivalent substitutes necessary for ongoing design support and procurement.

DIACs are used in AC switching applications, particularly in triac gate triggering circuits and phase control applications. The obsolete status of the DC34-TP requires identification of functionally equivalent active alternatives to maintain supply chain continuity.

Substiute Parts

DC34-TP

Micro Commercial CoIn Stock: 1102DC34-TP Datasheet

Current PartRFQ

DB4

STMicroelectronicsIn Stock: 20892DB4 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the DC34-TP is determined by the following critical parameters:

• Breakover Voltage Range: The substitute must operate within or overlap the 30–38V specification. The DB4 operates at 35–45V, providing overlap in the 35–38V range.
• Peak Output Current: Both parts must support minimum 2A peak output current for equivalent circuit performance.
• Package Compatibility: Both parts use DO-35 axial packaging, ensuring mechanical and electrical compatibility in existing PCB layouts.
• Temperature Rating: Operating range must match or exceed –40°C to 125°C.
• Compliance Standards: RoHS3 compliance is maintained across both parts.

The DB4 qualifies as a functional substitute based on these parameters, with the caveat that its higher breakover voltage range (35–45V versus 30–38V) represents a design consideration for applications requiring the lower voltage threshold of the original part.

Parameter Comparison

Engineering Selection Recommendations

The DB4 (STMicroelectronics) is the identified substitute for the obsolete DC34-TP. Selection is based on:

• Active Product Status: The DB4 maintains active manufacturing status, ensuring long-term availability and supply chain reliability.
• Compliance Alignment: Both parts meet ROHS3 compliance and share identical moisture sensitivity ratings.
• Electrical Compatibility: Peak output current (2A) and temperature operating range (–40°C to 125°C) are identical.
• Package Equivalence: DO-35 axial packaging ensures direct mechanical substitution in existing designs.

The DB4 breakover voltage range (35–45V) overlaps with the DC34-TP specification (30–38V) in the 35–38V window. Applications requiring operation below 35V breakover threshold should conduct circuit analysis to confirm the higher voltage threshold does not impact intended function.

Frequently Asked Questions (FAQ)

Q: Can the DB4 be used as a direct replacement for the DC34-TP in all applications?

A: The DB4 is mechanically and electrically compatible in DO-35 axial package applications. However, the DB4 breakover voltage minimum (35V) is higher than the DC34-TP minimum (30V). Applications designed for the lower voltage threshold must be evaluated to confirm the DB4 operates within acceptable circuit parameters.

Q: What is the significance of the different breakover voltage ranges?

A: Breakover voltage determines the threshold at which the DIAC conducts. The DC34-TP triggers between 30–38V, while the DB4 triggers between 35–45V. In circuits operating near 30–35V, the DB4 may not trigger reliably. In circuits operating above 35V, both parts function equivalently within their respective ranges.

Q: Are the package dimensions identical between DC34-TP and DB4?

A: Both parts use DO-35 axial packaging (DO-204AH designation), ensuring identical lead spacing, body dimensions, and PCB footprint compatibility.

Q: What is the difference in breakover current specifications?

A: The DC34-TP specifies 100 µA breakover current, while the DB4 specifies 50 µA. This represents the gate current required to trigger conduction. The lower breakover current of the DB4 may result in faster triggering response in gate-driven applications.

Q: Is the DB4 RoHS compliant?

A: Yes, the DB4 is ROHS3 compliant, matching the compliance status of the DC34-TP.