MF-LS190 Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The MF-LS190 is an active polymeric PTC resettable fuse manufactured by Bourns Inc., rated for 24V maximum voltage with 1.9A hold current. This component functions as an automatic reset protection device in electronic circuits, interrupting current flow during overcurrent conditions and restoring operation once the fault is cleared. The strap package configuration provides user-defined mounting flexibility. Substitute parts are identified when equivalent electrical performance and mechanical compatibility can be maintained within the specified parameter ranges for this product category.

Key Parameters

Parameter	Value
Voltage - Max	24V
Current - Hold (Ih) (Max)	1.9 A
Current - Trip (It)	4.2 A
Current - Max	100 A
Time to Trip	3 s
Resistance - Initial (Ri) (Min)	30 mOhms
Resistance - Post Trip (R1) (Max)	100 mOhms
Operating Temperature	-40°C ~ 85°C
Type	Polymeric
Package / Case	Strap
Product Status	Active
RoHS Status	ROHS3 Compliant
Approval Agency	cURus, TUV

Substitute Part Grouping Explanation

Substitution eligibility for polymeric PTC resettable fuses is determined by the following critical parameters:

Electrical Compatibility Criteria:

Maximum voltage rating must equal or exceed the application requirement (24V for MF-LS190)
Hold current (Ih) must match the specified value (1.9A)
Trip current (It) and time-to-trip characteristics must fall within acceptable operating margins
Initial and post-trip resistance values must remain within functional limits
Operating temperature range must encompass the application environment (-40°C ~ 85°C)

Mechanical & Regulatory Criteria:

Package type must be strap configuration for mounting compatibility
Type must be polymeric PTC resettable fuse
Regulatory compliance (cURus, TUV approval; ROHS3 compliance) must be maintained

The substitute part 0ZSC0190FF1E from Bel Fuse Inc. meets these criteria with the following considerations: maximum voltage is rated at 20V (lower than the 24V main part), hold current matches at 1.9A, and all regulatory certifications align with the main part specifications.

Parameter Comparison

Parameter	MF-LS190 (Bourns)	0ZSC0190FF1E (Bel Fuse)
Manufacturer	Bourns Inc.	Bel Fuse Inc.
Voltage - Max	24V	20V
Current - Hold (Ih) (Max)	1.9 A	1.9 A
Current - Trip (It)	4.2 A	3.9 A
Current - Max	100 A	100 A
Time to Trip	3 s	5 s
Resistance - Initial (Ri) (Min)	30 mOhms	39 mOhms
Resistance - Post Trip (R1) (Max)	100 mOhms	102 mOhms
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C
Type	Polymeric	Polymeric
Package / Case	Strap	Strap
Product Status	Active	Active
RoHS Status	ROHS3 Compliant	ROHS3 Compliant
Approval Agency	cURus, TUV	cURus, TUV
Size / Dimension	0.880" L x 0.417" W (22.35mm x 10.60mm)	0.827" L x 0.205" W (21.00mm x 5.20mm)
Thickness (Max)	0.043" (1.10mm)	0.039" (1.00mm)

Engineering Selection Recommendations

Both the MF-LS190 and 0ZSC0190FF1E maintain active product status with identical regulatory certifications (cURus, TUV approval) and ROHS3 compliance. Selection between these parts depends on application voltage requirements. The MF-LS190 is specified for 24V maximum voltage operation, while the 0ZSC0190FF1E is rated for 20V maximum voltage. Applications operating at voltages exceeding 20V require the MF-LS190. For applications operating at 20V or below, both parts satisfy regulatory and compliance requirements. Mechanical dimensions differ between the two parts; physical space constraints within the assembly must be evaluated against the provided dimensional specifications.

Frequently Asked Questions (FAQ)

Q: Can the 0ZSC0190FF1E substitute for the MF-LS190 in all applications?

A: Substitution is valid only for applications where the maximum operating voltage does not exceed 20V. The 0ZSC0190FF1E is rated for 20V maximum, while the MF-LS190 is rated for 24V. Applications requiring 24V operation must use the MF-LS190.

Q: What is the significance of the hold current (Ih) matching at 1.9A?

A: The hold current defines the maximum continuous current the fuse allows without tripping. Both parts maintain 1.9A hold current, ensuring equivalent steady-state circuit protection performance in applications designed for this specification.

Q: How do the trip current (It) values differ between these parts?

A: The MF-LS190 trips at 4.2A while the 0ZSC0190FF1E trips at 3.9A. This 0.3A difference affects overcurrent response sensitivity. Applications with specific trip current requirements must match the appropriate part.

Q: Are the strap package dimensions interchangeable?

A: Both parts use strap packaging, but physical dimensions differ. The MF-LS190 measures 0.880" L x 0.417" W (22.35mm x 10.60mm), while the 0ZSC0190FF1E measures 0.827" L x 0.205" W (21.00mm x 5.20mm). Physical space availability in the assembly must be confirmed before substitution.

Q: Do both parts meet the same regulatory standards?

A: Yes. Both the MF-LS190 and 0ZSC0190FF1E carry cURus and TUV approvals and are ROHS3 compliant, meeting identical regulatory requirements for this product category.

Q: What is the impact of the 2-second difference in time-to-trip?

A: The MF-LS190 trips in 3 seconds while the 0ZSC0190FF1E trips in 5 seconds. This affects the response time to overcurrent conditions. Applications with specific time-to-trip requirements must use the part matching that specification.

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