SMD075-2 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The SMD075-2 is a Polymeric PTC Resettable Fuse manufactured by Littelfuse Inc., rated for 30V maximum voltage and 750 mA hold current in a 2920 (7351 Metric) surface mount package. This component is classified as Obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Polymeric PTC resettable fuses provide automatic overcurrent protection by increasing resistance when current exceeds the trip threshold, then resetting when the fault condition is removed. The SMD075-2 serves in circuit protection applications requiring 750 mA hold current with 1.5 A trip current characteristics.

Substiute Parts

SMD075-2

Littelfuse Inc.In Stock: 3495SMD075-2 Datasheet

Current PartRFQ

SMD075F-2

Littelfuse Inc.In Stock: 19504SMD075F-2 Datasheet

DirectRFQ

MF-SM075-2

Bourns Inc.In Stock: 6160MF-SM075-2 Datasheet

DirectRFQ

0ZCF0075FF2C

Bel Fuse Inc.In Stock: 256050ZCF0075FF2C Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SMD075-2 is determined by the following critical parameters:

Primary Matching Criteria:

• Current - Hold (Ih): 750 mA (exact match required)
• Current - Trip (It): 1.5 A (exact match required)
• Voltage - Max: 30V minimum (equal or higher acceptable)
• Operating Temperature: -40°C ~ 85°C (equal or wider range acceptable)
• Mounting Type: Surface Mount (required)
• Time to Trip: 300 ms (exact match required)

Secondary Compatibility Factors:

• Package footprint compatibility (2920 or 2-SMD equivalent)
• Physical dimensions within tolerance
• Resistance characteristics (Ri and R1) within functional range
• RoHS and regulatory compliance status

The three substitute parts listed below meet these criteria with varying degrees of parameter alignment and compliance status.

Parameter Comparison

Engineering Selection Recommendations

SMD075F-2 (Littelfuse Inc.)

This substitute provides the closest functional equivalence to the SMD075-2. Electrical parameters are identical across all critical specifications: 30V voltage rating, 750 mA hold current, 1.5 A trip current, and 300 ms trip time. The primary difference is product status (Active vs. Obsolete) and RoHS3 compliance. The 2-SMD package differs from the original 2920 package; PCB layout verification is required to confirm footprint compatibility. Identical initial resistance (350 mOhms) ensures equivalent circuit behavior. Recommended for direct replacement in new designs where RoHS3 compliance is required.

MF-SM075-2 (Bourns Inc.)

This Multifuse® alternative meets all critical electrical parameters with identical hold current, trip current, and trip time. The 30V voltage rating matches the original specification. Key differentiators include lower initial resistance (230 mOhms vs. 350 mOhms), higher maximum current rating (80 A vs. 40 A), and superior moisture sensitivity (MSL 1 vs. 2A). AEC-Q200 qualification provides automotive-grade reliability. The 2-SMD package requires footprint verification. Recommended for applications requiring enhanced moisture resistance and automotive compliance.

0ZCF0075FF2C (Bel Fuse Inc.)

This substitute offers the highest voltage margin (33V vs. 30V) and maximum current rating (100 A). All critical protection parameters match: 750 mA hold current, 1.5 A trip current, and 300 ms trip time. Initial resistance is lower (180 mOhms), providing reduced circuit loading. The 2920 (7351 Metric) package matches the original form factor, simplifying PCB integration. AEC-Q200 and cURus certifications provide automotive and regulatory compliance. Concave package geometry differs from the original; mechanical clearance verification is necessary. Recommended for applications requiring maximum voltage headroom and automotive qualification.

Frequently Asked Questions (FAQ)

Q: Can SMD075F-2 replace SMD075-2 directly on existing PCBs?

A: Electrical substitution is valid; however, the package change from 2920 to 2-SMD requires PCB footprint verification. Physical dimensions differ slightly (0.290" L x 0.202" W for both, but 2-SMD is a different land pattern). Consult PCB layout documentation before implementation.

Q: What is the significance of the lower initial resistance in MF-SM075-2 and 0ZCF0075FF2C?

A: Lower initial resistance (Ri) reduces voltage drop across the fuse during normal operation, resulting in lower power dissipation and heat generation. This is advantageous in low-voltage, high-current applications. Verify that circuit design tolerates the reduced voltage drop.

Q: Why does 0ZCF0075FF2C have a 33V rating instead of 30V?

A: The higher voltage rating provides additional safety margin in circuits operating near the 30V limit. This does not affect substitution validity; 33V-rated components are suitable for 30V applications. The higher rating indicates greater dielectric strength.

Q: Are there package compatibility issues between 2920 and 2-SMD formats?

A: Yes. The 2920 (7351 Metric) and 2-SMD packages have different land patterns and footprints. Physical dimensions are similar, but PCB pad layouts differ. Verify footprint compatibility in your design software before selecting a substitute with a different package designation.

Q: Which substitute is recommended for new designs?

A: SMD075F-2 provides the closest electrical match with RoHS3 compliance and active product status. For automotive applications, MF-SM075-2 or 0ZCF0075FF2C are preferred due to AEC-Q200 qualification. Package compatibility must be confirmed for all options.

Q: What is the impact of MSL (Moisture Sensitivity Level) differences?

A: MF-SM075-2 has MSL 1 (Unlimited shelf life), while SMD075-2, SMD075F-2, and 0ZCF0075FF2C have MSL 2A (4 weeks). Lower MSL values indicate greater tolerance to moisture exposure during storage and handling. For applications with extended storage periods or humid environments, MF-SM075-2 offers superior reliability.

Q: Can these substitutes be used interchangeably in the same circuit?

A: Electrical interchangeability is confirmed for all three substitutes based on hold current, trip current, and trip time specifications. However, package differences and slight variations in initial resistance require individual PCB layout verification and circuit simulation to confirm functional equivalence in your specific application.