LTP190 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The LTP190 is a polymeric PTC resettable fuse manufactured by Littelfuse Inc., rated for 24V with a 1.9A hold current. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations. The PolySwitch® LTP series provides overcurrent protection through polymeric positive temperature coefficient technology, automatically resetting after fault conditions are cleared.

Substiute Parts

LTP190

Littelfuse Inc.In Stock: 1196LTP190 Datasheet

Current PartRFQ

MF-LS190

Bourns Inc.In Stock: 1062MF-LS190 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LTP190 is determined by strict equivalence across electrical and mechanical parameters. The primary substitute, MF-LS190 from Bourns Inc., qualifies as a direct equivalent based on the following criteria:

Electrical parameters match exactly: 24V maximum voltage, 1.9A hold current, 4.2A trip current, 3-second trip time, 30 mOhms minimum initial resistance, and 100 mOhms maximum post-trip resistance. Mechanical compatibility is confirmed through identical package type (Strap), dimensions (0.880" L x 0.417" W / 22.35mm x 10.60mm), and thickness (0.043" / 1.10mm). Both components employ polymeric PTC technology with identical current and voltage ratings, ensuring functional interchangeability in circuit protection applications.

Parameter Comparison

Engineering Selection Recommendations

The MF-LS190 from Bourns Inc. is the direct functional equivalent for the obsolete LTP190. Selection of the MF-LS190 is supported by:

Active product status ensures ongoing availability and manufacturer support, eliminating supply chain risk associated with obsolete components. ROHS3 compliance of the MF-LS190 meets current environmental regulations, whereas the LTP190 is non-compliant. Third-party certifications (cURus, TUV) on the MF-LS190 provide additional validation for safety-critical applications. Improved moisture sensitivity rating (MSL 1 vs. MSL 2A) on the MF-LS190 offers superior storage and handling characteristics.

Electrical and mechanical parameters are identical, ensuring drop-in compatibility without circuit redesign or mechanical modification.

Frequently Asked Questions (FAQ)

Q: Can the MF-LS190 directly replace the LTP190 without circuit modification?

A: Yes. Electrical parameters (voltage, current ratings, trip characteristics, resistance values) and mechanical dimensions are identical. The MF-LS190 functions as a direct substitute in existing LTP190 applications.

Q: What is the primary reason to transition from LTP190 to MF-LS190?

A: The LTP190 is obsolete. The MF-LS190 is an active product with identical electrical and mechanical specifications, ensuring long-term availability and supply chain continuity.

Q: Are there compliance differences between these parts?

A: Yes. The MF-LS190 is ROHS3 compliant with cURus and TUV certifications, while the LTP190 is RoHS non-compliant. For new designs or regulated applications, the MF-LS190 is the appropriate selection.

Q: How do moisture sensitivity levels affect component handling?

A: The MF-LS190 has MSL 1 (unlimited shelf life), while the LTP190 has MSL 2A (4-week limit). The MF-LS190 offers more flexible storage and handling without time-dependent degradation.

Q: Are the strap package dimensions identical?

A: Yes. Both components measure 0.880" L x 0.417" W (22.35mm x 10.60mm) with 0.043" (1.10mm) maximum thickness, confirming mechanical interchangeability in user-defined mounting configurations.

Q: What is the operating temperature range for these components?

A: The MF-LS190 specifies -40°C to 85°C. Operating temperature for the LTP190 is not provided in available documentation.