LTP100 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The LTP100 is a polymeric PTC resettable fuse manufactured by Littelfuse Inc., rated for 24V maximum voltage with 1A hold current. This component is classified as obsolete, making identification of active equivalent parts essential for ongoing system support and new design implementations. The PolySwitch® LTP series provides circuit protection through automatic current limiting without requiring manual replacement after trip events.

Substiute Parts

LTP100

Littelfuse Inc.In Stock: 951LTP100 Datasheet

Current PartRFQ

MF-LS100

Bourns Inc.In Stock: 2777MF-LS100 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LTP100 is determined by strict equivalence across the following electrical and mechanical parameters:

• Voltage rating: 24V maximum
• Hold current: 1A maximum
• Trip current: 2.5A
• Time to trip: 7 seconds
• Initial resistance: 70 mOhms minimum
• Post-trip resistance: 260 mOhms maximum
• Operating temperature range: -40°C to 85°C
• Package type: Strap configuration
• Physical dimensions: 22.00mm L x 5.05mm W x 1.00mm thickness maximum

The MF-LS100 from Bourns Inc. meets all specified electrical and mechanical parameters, establishing it as a direct functional equivalent within the polymeric PTC resettable fuse category.

Parameter Comparison

Engineering Selection Recommendations

The MF-LS100 serves as the active equivalent for the obsolete LTP100. Both components carry identical electrical specifications and physical dimensions, ensuring direct functional compatibility in circuit protection applications. The MF-LS100 maintains active product status with improved regulatory compliance, meeting ROHS3 requirements compared to the LTP100's non-compliant status. Both parts carry CSA, TUV, and UL certifications, confirming suitability for safety-critical applications. The MF-LS100 offers superior moisture sensitivity characteristics (MSL 1 versus MSL 2A), providing extended shelf life and storage flexibility.

Frequently Asked Questions (FAQ)

Q: Can the MF-LS100 directly replace the LTP100 in existing designs? A: Yes. The MF-LS100 matches all electrical parameters (voltage, hold current, trip current, time to trip, and resistance values) and physical dimensions of the LTP100, enabling direct substitution without circuit modification.

Q: What is the significance of the product status difference? A: The LTP100 is obsolete, indicating discontinued manufacturing and limited availability. The MF-LS100 is active, ensuring reliable supply chain access and ongoing manufacturer support.

Q: How do RoHS compliance differences affect component selection? A: The MF-LS100 meets ROHS3 compliance standards, while the LTP100 does not. For applications subject to RoHS regulations or customer requirements, the MF-LS100 is the appropriate selection.

Q: Are there packaging differences between these components? A: Both components use identical strap packaging with matching dimensions (22.00mm L x 5.05mm W x 1.00mm thickness). No mechanical redesign is required for substitution.

Q: What certifications apply to both parts? A: Both the LTP100 and MF-LS100 carry CSA, TUV, and UL approvals, confirming compliance with recognized safety standards for circuit protection devices.

Q: Does the moisture sensitivity level affect performance? A: The MF-LS100 features MSL 1 (unlimited storage), compared to the LTP100's MSL 2A (4 weeks). This provides extended shelf life and reduced risk of moisture-related degradation during storage and handling.