LTP190F Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The LTP190F is a polymeric PTC resettable fuse manufactured by Littelfuse Inc., rated for 24V maximum voltage with a 1.9A hold current. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and component procurement.

PTC resettable fuses provide automatic overcurrent protection by increasing resistance when current exceeds the trip threshold, then returning to normal operation once the fault condition clears. The LTP190F's strap mounting configuration and electrical ratings define its application scope in 24V circuit protection.

Substiute Parts

LTP190F

Littelfuse Inc.In Stock: 955LTP190F Datasheet

Current PartRFQ

MF-LS190

Bourns Inc.In Stock: 1062MF-LS190 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LTP190F is determined by strict equivalence across electrical and mechanical parameters. The following criteria establish functional interchangeability:

Electrical Parameters (Critical):

• Maximum voltage rating: 24V
• Hold current (Ih): 1.9 A
• Trip current (It): 4.2 A
• Maximum current: 100 A
• Time to trip: 3 s
• Initial resistance (Ri): 30 mOhms minimum
• Post-trip resistance (R1): 100 mOhms maximum

Mechanical Parameters (Critical):

• Package type: Strap
• Physical dimensions: 0.880" L x 0.417" W (22.35mm x 10.60mm)
• Thickness: 0.043" (1.10mm) maximum
• Mounting type: User Defined

Compliance Parameters:

• Polymeric PTC type
• RoHS3 compliance

The MF-LS190 manufactured by Bourns Inc. meets all specified electrical and mechanical parameters, establishing it as a direct functional equivalent.

Parameter Comparison

Engineering Selection Recommendations

The MF-LS190 from Bourns Inc. is the direct equivalent for the obsolete LTP190F. Selection is based on the following factors:

Electrical Equivalence: All critical electrical parameters match exactly, including voltage rating, hold current, trip current, and resistance characteristics. The 3-second trip time and 100A maximum current rating are identical.

Mechanical Compatibility: Physical dimensions and strap package configuration are identical, ensuring direct mechanical substitution in existing designs without layout modifications.

Compliance Status: Both components are ROHS3 compliant and carry equivalent regulatory approvals (CSA, TUV, UL for LTP190F; cURus, TUV for MF-LS190).

Product Availability: The MF-LS190 is in active production status with confirmed inventory availability, addressing the obsolescence of the LTP190F.

Frequently Asked Questions (FAQ)

Q: Can the MF-LS190 be used as a direct replacement for the LTP190F?

A: Yes. The MF-LS190 meets all electrical and mechanical specifications of the LTP190F, including voltage rating, current ratings, resistance characteristics, physical dimensions, and package type.

Q: Are there differences in operating temperature ranges between these parts?

A: The MF-LS190 specifies an operating temperature range of -40°C to 85°C. The LTP190F does not provide an operating temperature specification in the available data. Both components are suitable for standard industrial applications within this range.

Q: What is the difference in moisture sensitivity between these parts?

A: The LTP190F is rated MSL 2A (4 weeks), while the MF-LS190 is rated MSL 1 (Unlimited). The MF-LS190 offers superior moisture resistance, reducing handling and storage constraints.

Q: Are the strap mounting configurations identical?

A: Yes. Both components use user-defined strap mounting with identical physical dimensions (0.880" L x 0.417" W, 22.35mm x 10.60mm) and thickness (0.043" / 1.10mm maximum).

Q: Do both parts carry the same regulatory approvals?

A: Both components are ROHS3 compliant and carry TUV approval. The LTP190F additionally lists CSA and UL approvals, while the MF-LS190 lists cURus approval. Both meet standard industrial certification requirements.