LTP100F Polymeric PTC Resettable Fuse - Equivalent & Substitute Parts

Part Overview

The LTP100F is a polymeric PTC resettable fuse manufactured by Littelfuse, rated for 24V maximum voltage with 1A hold current. This component functions as an automatic reset protection device, interrupting circuit current when thermal conditions exceed design thresholds and restoring operation when the fault clears.

The LTP100F carries an Obsolete product status. Identifying qualified substitute components ensures design continuity and supply chain reliability for applications currently utilizing this part.

Substiute Parts

LTP100F

LittelfuseIn Stock: 1007LTP100F Datasheet

Current PartRFQ

MF-LS100

Bourns Inc.In Stock: 2777MF-LS100 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LTP100F is determined by electrical and mechanical parameter equivalence across the following criteria:

Electrical Parameters: Maximum voltage rating (24V), hold current (1A maximum), trip current (2.5A), maximum current capacity (100A), and time-to-trip response (7 seconds) must match exactly.

Resistance Characteristics: Initial resistance minimum (70 mOhms) and post-trip resistance maximum (260 mOhms) define the thermal and electrical behavior during normal and fault conditions.

Mechanical Compatibility: Package type (Strap), physical dimensions (22.00mm L x 5.05mm W x 1.00mm thickness maximum), and mounting configuration must accommodate existing circuit board layouts and assembly processes.

Environmental and Compliance: Operating temperature range (-40°C to 85°C), RoHS3 compliance, and regulatory approvals (CSA, TUV, UL) ensure functional equivalence in target applications.

Parameter Comparison

Engineering Selection Recommendations

The MF-LS100 (Bourns Inc., Multifuse® series) provides direct electrical and mechanical equivalence to the obsolete LTP100F. Both components satisfy identical voltage, current, resistance, and thermal specifications within the specified operating temperature range.

Product status differentiation: The LTP100F is classified as Obsolete, while the MF-LS100 maintains Active status, ensuring ongoing availability and manufacturing support.

Regulatory compliance: Both components carry ROHS3 compliance and equivalent approval agency certifications (CSA, TUV). The MF-LS100 includes UL certification in addition to CSA and TUV.

Moisture sensitivity: The MF-LS100 specifies MSL 1 (Unlimited), compared to the LTP100F MSL 2A (4 Weeks), indicating superior moisture resistance characteristics for the substitute component.

Frequently Asked Questions (FAQ)

Q: Can the MF-LS100 directly replace the LTP100F in existing designs?

A: Yes. The MF-LS100 matches all specified electrical parameters (voltage, current ratings, resistance values, trip time) and mechanical dimensions (package type, physical size, thickness). No circuit redesign is required.

Q: Are there differences in packaging or handling between these components?

A: Both components use identical Strap package configuration and physical dimensions (22.00mm x 5.05mm x 1.00mm maximum). The MF-LS100 offers improved moisture sensitivity rating (MSL 1 versus MSL 2A), reducing storage and handling constraints.

Q: What certifications apply to the MF-LS100?

A: The MF-LS100 carries CSA, TUV, and UL approvals. Both components are ROHS3 compliant and REACH unaffected.

Q: Why is the LTP100F listed as Obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. The MF-LS100 provides equivalent functionality with active manufacturing support and improved availability.

Q: Are there inventory considerations for this substitution?

A: The MF-LS100 maintains higher stock levels (2718 pieces) compared to remaining LTP100F inventory (953 pieces), supporting long-term supply chain continuity.