CQ3P-40N Equivalent & Substitute Parts

Part Overview

The CQ3P-40N is a TRIAC rated for 40A at 800V in TO-3 packaging, manufactured by Central Semiconductor Corp. This component is classified as obsolete, making direct sourcing increasingly difficult. Identifying equivalent substitute parts ensures design continuity and maintains system reliability for applications requiring 40A, 800V thyristor functionality.

Substiute Parts

CQ3P-40N

Central Semiconductor CorpIn Stock: 945CQ3P-40N Datasheet

Current PartRFQ

BTA40-800B

STMicroelectronicsIn Stock: 1843BTA40-800B Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the CQ3P-40N is determined by matching the following critical electrical parameters:

• Voltage rating (Off State): 800V minimum
• Current rating (On State): 40A minimum
• Device type: TRIAC (Standard configuration)
• Thermal operating range: Compatible with -40°C to 125°C applications

The BTA40-800B from STMicroelectronics meets these substitution criteria. Both devices are standard TRIACs with identical voltage and current ratings. The BTA40-800B is currently in active production status, providing long-term availability compared to the obsolete CQ3P-40N.

Parameter Comparison

Engineering Selection Recommendations

The BTA40-800B is the direct electrical equivalent for the CQ3P-40N, matching both the 40A current and 800V voltage specifications. The substitute part is currently in active production status, ensuring availability for new designs and replacement applications.

The BTA40-800B carries ROHS3 compliance and REACH unaffected status, meeting modern regulatory requirements. The RD91-3 insulated package provides thermal management suitable for chassis mount applications. Gate trigger specifications (Vgt: 1.3V max, Igt: 50mA max) and hold current (Ih: 80mA max) are within standard TRIAC operating parameters.

Physical package differences exist between the TO-3 and RD91-3 configurations. PCB layout and mounting hardware must be evaluated during integration to ensure mechanical compatibility with existing designs.

Frequently Asked Questions (FAQ)

Q: Can the BTA40-800B directly replace the CQ3P-40N without circuit modifications?

A: The BTA40-800B matches the electrical specifications (40A, 800V) required for functional substitution. However, package differences between TO-3 and RD91-3 require mechanical redesign of the mounting interface and PCB layout.

Q: What are the key electrical parameters that define substitution compatibility?

A: Substitution is determined by matching the off-state voltage rating (800V) and on-state current rating (40A). Both devices are standard TRIAC configurations with compatible gate trigger and hold current characteristics.

Q: Is the BTA40-800B suitable for new designs?

A: Yes. The BTA40-800B is in active production status with ROHS3 compliance and REACH unaffected designation, making it appropriate for new product development and long-term supply chain planning.

Q: What is the difference between the TO-3 and RD91-3 packages?

A: TO-3 is a threaded stud package, while RD91-3 is an insulated chassis mount package. Both provide thermal management but require different mounting hardware and PCB design considerations.

Q: Are there any compliance or regulatory differences between the two parts?

A: The BTA40-800B provides documented ROHS3 compliance and REACH unaffected status. The CQ3P-40N compliance information is not specified in available data.