MF-S200S Polymeric PTC Resettable Fuse Equivalent & Substitute Parts

Part Overview

The MF-S200S is a polymeric PTC resettable fuse manufactured by Bourns Inc. in the Multifuse® MF-S series. This component is rated for 30V maximum voltage with a 2A hold current and 4.4A trip current, designed for strap mounting applications. The MF-S200S is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and procurement continuity. Active alternatives are available from both Bourns Inc. and Littelfuse Inc. that maintain electrical compatibility within defined parameter ranges.

Substiute Parts

MF-S200S

Bourns Inc.In Stock: 1156MF-S200S Datasheet

Current PartRFQ

MF-S200

Bourns Inc.In Stock: 6391MF-S200 Datasheet

DirectRFQ

SRP350F

Littelfuse Inc.In Stock: 50377SRP350F Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the MF-S200S are classified based on electrical parameter compatibility within the polymeric PTC resettable fuse category. The substitution logic is determined by the following critical parameters:

Voltage Rating: All substitute parts must maintain the 30V maximum voltage specification to ensure safe operation within the original circuit design envelope.

Hold Current (Ih): The 2A hold current is the primary current threshold. Substitute parts with equal or higher hold current ratings are electrically compatible, as they will not trip under normal operating conditions at or below this current level.

Trip Current (It) and Time to Trip: These parameters define the fault protection response. Substitutes with comparable trip current and response time characteristics maintain the protective function of the original design.

Resistance Characteristics: Initial resistance (Ri) and post-trip resistance (R1) affect circuit performance and heat dissipation. Substitutes with similar or lower resistance values are compatible.

Package and Mounting: Strap mounting configuration is maintained across all substitutes to ensure mechanical compatibility.

Compliance and Certifications: RoHS3 compliance and approval agencies (cURus, TUV, UL, CSA) confirm regulatory equivalence.

Parameter Comparison

Engineering Selection Recommendations

MF-S200 (Direct Substitute): This part is the primary replacement for the obsolete MF-S200S. Both components are manufactured by Bourns Inc. and share identical electrical specifications: 30V voltage rating, 2A hold current, 4.4A trip current, 4-second trip time, and equivalent resistance characteristics. The MF-S200 is currently in active production status with higher inventory availability. Packaging differs only in format (bulk versus strap designation), with no impact on electrical or mechanical function. Both parts carry ROHS3 compliance and cURus/TUV certifications. This substitute provides direct functional equivalence with no design modifications required.

SRP350F (Similar Substitute): This Littelfuse Inc. PolySwitch® SRP series component operates at the same 30V maximum voltage and maintains the same operating temperature range. The SRP350F has a higher hold current rating (4.6A versus 2A) and correspondingly higher trip current (6.3A versus 4.4A), with a faster trip time of 3 seconds. Initial and post-trip resistance values are lower (17 mOhms and 50 mOhms respectively). This part is suitable for applications where the higher current rating and faster response time are acceptable or beneficial. The SRP350F carries broader certification coverage (CSA, TUV, UL) and ROHS3 compliance. Physical dimensions differ slightly (1.185" L x 0.522" W versus 0.880" L x 0.417" W), requiring verification of mechanical fit within the application.

Frequently Asked Questions (FAQ)

Q: Can MF-S200 directly replace MF-S200S without circuit modifications?

A: Yes. The MF-S200 is electrically and mechanically identical to the MF-S200S. Both components share the same voltage rating (30V), hold current (2A), trip current (4.4A), trip time (4s), and resistance characteristics. The only difference is product status (active versus obsolete) and packaging format. No design changes are required.

Q: Is SRP350F a direct replacement for MF-S200S?

A: SRP350F is a compatible substitute with higher current ratings. It maintains the 30V voltage specification and operating temperature range but has a 4.6A hold current (versus 2A) and 6.3A trip current (versus 4.4A). The faster trip time (3s versus 4s) and lower resistance values may alter circuit behavior. Mechanical dimensions also differ. Verify that the higher current ratings and faster response time are acceptable for your application before substitution.

Q: What are the key parameters that determine substitution compatibility?

A: Voltage rating, hold current, trip current, trip time, and resistance characteristics are the primary electrical parameters. Strap mounting configuration and operating temperature range must also be maintained. RoHS3 compliance and regulatory certifications (cURus, TUV, UL, CSA) confirm compliance equivalence. Physical dimensions must be verified for mechanical fit.

Q: Why does MF-S200S show as obsolete?

A: The MF-S200S is classified as obsolete by the manufacturer, indicating it is no longer in active production. The MF-S200 serves as the active production equivalent with identical specifications. For new designs or ongoing procurement, the MF-S200 is the recommended choice.

Q: Can I use SRP350F in a circuit designed for MF-S200S?

A: SRP350F can be used if the circuit design accommodates higher hold and trip current ratings (4.6A and 6.3A respectively) and faster trip response (3s). The lower resistance values may reduce voltage drop and heat generation. Verify mechanical fit, as physical dimensions differ. If the circuit requires the exact 2A hold current and 4-second trip time, use MF-S200 instead.

Q: Are there inventory or lead time considerations for these substitutes?

A: MF-S200 has 6,341 pieces in stock (bulk packaging). SRP350F has 50,341 pieces in stock. Both are active production parts with established supply chains. MF-S200S (1,079 pieces) is obsolete and inventory is limited.