MCH3478-TL-W-Z Equivalent & Substitute Parts

Part Overview

The MCH3478-TL-W-Z is a P-Channel MOSFET rated for 30V operation with 1.6A continuous drain current in a SC-70FL surface mount package. This component is classified as obsolete, necessitating identification of active equivalent parts for new designs and ongoing production requirements. The substitute part maintains functional compatibility while offering improved availability and active product status.

Substiute Parts

MCH3478-TL-W-Z

onsemiIn Stock: 1213MCH3478-TL-W-Z Datasheet

Current PartRFQ

NTS4173PT1G

onsemiIn Stock: 17148NTS4173PT1G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The NTS4173PT1G qualifies as a direct substitute for the MCH3478-TL-W-Z based on the following alignment of critical electrical and mechanical parameters:

Matching Parameters:

• FET Type: Both are P-Channel MOSFETs
• Drain to Source Voltage (Vdss): Both rated at 30V
• Gate to Source Voltage (Vgs Max): Both rated at ±12V
• Package Family: Both utilize SC-70 surface mount technology (SC-70FL vs SC-70-3/SOT323)
• RoHS Compliance: Both ROHS3 Compliant
• Moisture Sensitivity Level: Both MSL 1 (Unlimited)
• REACH Status: Both REACH Unaffected

Current Rating Consideration: The NTS4173PT1G provides 1.2A continuous drain current compared to the MCH3478-TL-W-Z at 1.6A. This represents a 25% reduction in current capacity. Substitution is valid only for applications where the required continuous drain current does not exceed 1.2A at 25°C.

Product Status: The NTS4173PT1G maintains active product status with substantial inventory availability (17,100 pieces), whereas the MCH3478-TL-W-Z is obsolete with limited remaining stock (1,115 pieces).

Parameter Comparison

Engineering Selection Recommendations

The NTS4173PT1G is suitable as a substitute for the MCH3478-TL-W-Z in applications meeting the following conditions:

Electrical Compatibility:

• Required continuous drain current does not exceed 1.2A at 25°C ambient temperature
• Gate drive voltage capability supports the 2.5V to 10V range specified for the NTS4173PT1G
• Circuit design accommodates the higher on-resistance characteristics of the substitute part

Compliance & Certification: Both parts maintain identical RoHS3 compliance, MSL 1 rating, and REACH unaffected status, ensuring regulatory equivalence for applications subject to these requirements.

Availability & Product Lifecycle: The NTS4173PT1G provides active product status with high inventory availability, eliminating obsolescence risk associated with the MCH3478-TL-W-Z. This substitution is appropriate for new designs and production continuity planning.

Package Compatibility: Both parts utilize SC-70 surface mount technology. PCB footprints designed for SC-70FL are compatible with SC-70-3 (SOT323) placement, though component outline verification is required for specific board layouts.

Frequently Asked Questions (FAQ)

Q: Can the NTS4173PT1G directly replace the MCH3478-TL-W-Z in all applications?

A: No. The NTS4173PT1G is rated for 1.2A continuous drain current compared to 1.6A for the MCH3478-TL-W-Z. Substitution is valid only when the application requires 1.2A or less. Applications requiring the full 1.6A rating require alternative solutions.

Q: What is the difference between SC-70FL and SC-70-3 packaging?

A: Both designations refer to the SC-70 surface mount package family. SC-70FL and SC-70-3 (SOT323) are minor variants within this family. PCB footprints designed for one variant are generally compatible with the other, though component outline documentation should be consulted for specific layout requirements.

Q: How do the drive voltage requirements differ between these parts?

A: The MCH3478-TL-W-Z operates with drive voltages between 1.8V and 4.5V for maximum on-resistance specification. The NTS4173PT1G requires drive voltages between 2.5V and 10V. Circuits designed for the lower drive voltage range of the original part may require gate driver adjustment when using the substitute.

Q: Are there any compliance differences between these parts?

A: No. Both parts are ROHS3 compliant, carry MSL 1 (Unlimited) moisture sensitivity rating, and are REACH unaffected. Regulatory and environmental compliance is equivalent.

Q: What is the primary reason to substitute the MCH3478-TL-W-Z?

A: The MCH3478-TL-W-Z is classified as obsolete. The NTS4173PT1G provides an active, readily available alternative from the same manufacturer with equivalent electrical and mechanical specifications within the stated current rating limitation.

Q: How should I verify compatibility for my specific application?

A: Confirm that your application requires continuous drain current of 1.2A or less at 25°C ambient temperature. Verify that your gate driver circuit can supply the 2.5V to 10V drive voltage range. Consult the detailed datasheets for both parts to confirm on-resistance and thermal characteristics meet your design requirements.