NCT3945S TR Equivalent & Substitute Parts

Part Overview

The NCT3945S TR is a linear fan driver integrated circuit manufactured by Nuvoton Technology Corporation, classified as a Power Management (PMIC) device in an 8SOP package. This component functions as a motor driver for fan control applications. The NCT3945S TR has reached obsolete product status, making identification of functionally equivalent alternatives necessary for ongoing design support, legacy system maintenance, and component procurement.

Substiute Parts

NCT3945S TR

Nuvoton Technology CorporationIn Stock: 1215NCT3945S TR Datasheet

Current PartRFQ

NCT3949 TR

Nuvoton Technology CorporationIn Stock: 672NCT3949 TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the NCT3945S TR is determined by the following critical parameters:

• Functional Category: Power Management (PMIC) with linear fan driver capability
• Package Type: 8SOP form factor
• Application: Motor driver functionality
• Moisture Sensitivity Level: MSL 1 (Unlimited) or equivalent
• Environmental Compliance: REACH Unaffected status

The NCT3949 TR meets all substitution criteria as a direct equivalent, sharing identical functional classification, package type, application purpose, and environmental compliance specifications. The primary distinction is product status transition from obsolete to active availability.

Parameter Comparison

Engineering Selection Recommendations

The NCT3949 TR is the manufacturer-recommended substitute for the obsolete NCT3945S TR. Both components share identical functional specifications, package configuration, and environmental compliance attributes. The NCT3949 TR maintains active product status with confirmed ROHS3 compliance, providing long-term supply chain stability and regulatory alignment for new designs and legacy system updates.

Selection between the main part and substitute should be based on:

• Availability requirements: NCT3945S TR stock (1127 units) versus NCT3949 TR stock (660 units)
• Regulatory compliance: NCT3949 TR explicitly certified ROHS3 Compliant
• Product lifecycle: NCT3949 TR active status ensures continued manufacturer support

Frequently Asked Questions (FAQ)

Q: Can the NCT3949 TR directly replace the NCT3945S TR in existing designs?

A: Yes. Both components share identical package type (8SOP), functional classification (linear fan driver), application purpose (motor driver), and environmental compliance specifications (MSL 1, REACH Unaffected). No design modifications are required for substitution.

Q: What is the primary reason for substitution?

A: The NCT3945S TR has reached obsolete product status. The NCT3949 TR is the manufacturer-designated equivalent with active availability and confirmed ROHS3 compliance.

Q: Are there any compliance differences between these parts?

A: The NCT3949 TR explicitly declares ROHS3 compliance, while the NCT3945S TR compliance status is not specified in available documentation. Both maintain REACH Unaffected status and MSL 1 rating.

Q: What is the package compatibility between these parts?

A: Both components use the 8SOP package type, ensuring mechanical and electrical compatibility in PCB layouts and socket configurations.

Q: Should I prioritize the remaining NCT3945S TR inventory or transition to NCT3949 TR?

A: Transition to NCT3949 TR is recommended for new designs and long-term applications due to active product status and explicit ROHS3 compliance. Existing NCT3945S TR inventory may be used for legacy system maintenance where supply is available.