FR2249-SURFACEMOUNT Equivalent & Substitute Parts

Part Overview

The FR2249-SURFACEMOUNT is a glass body reed switch manufactured by Coto Technology, configured as a single-pole single-throw normally open (SPST-NO) device. This surface mount component is rated for 500mA switching current at 200V (AC/DC) with a 10VA power rating and operates within a 15–25AT magnetic field range. The FR2 series component is classified as obsolete, necessitating identification of functionally compatible alternatives for ongoing design requirements and procurement needs.

Substiute Parts

FR2249-SURFACEMOUNT

Coto TechnologyIn Stock: 681FR2249-SURFACEMOUNT Datasheet

Current PartRFQ

MDSM-4R-12-18

Littelfuse Inc.In Stock: 10223MDSM-4R-12-18 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FR2249-SURFACEMOUNT is evaluated based on the following critical parameters:

Circuit Configuration: Both the main part and substitute must maintain SPST-NO topology to preserve switching logic and control functionality.

Switching Current Rating: The substitute must support the required 500mA switching current. The MDSM-4R-12-18 supports 350mA (AC) and 500mA (DC), meeting DC switching requirements.

Switching Voltage Rating: The substitute must accommodate the 200V switching voltage requirement. The MDSM-4R-12-18 provides 140V (AC) and 200V (DC), satisfying DC voltage specifications.

Power Rating: The substitute must support the 10VA/10W power envelope. Both parts are rated at 10VA/10W.

Operate Range: The substitute must function within a compatible magnetic field range. The FR2249-SURFACEMOUNT operates at 15–25AT; the MDSM-4R-12-18 operates at 12–18AT, representing a narrower but overlapping range.

Mounting and Termination: Both parts utilize surface mount technology with gull wing termination, ensuring mechanical and electrical compatibility with existing PCB layouts.

Environmental Compliance: Both parts are ROHS3 compliant and REACH unaffected, meeting regulatory requirements.

Parameter Comparison

Engineering Selection Recommendations

The MDSM-4R-12-18 manufactured by Littelfuse Inc. is an active product suitable for applications currently utilizing the obsolete FR2249-SURFACEMOUNT. Both components share identical circuit topology (SPST-NO), mounting methodology (surface mount with gull wing termination), and environmental operating range (–40°C to 125°C).

For DC-only applications, the MDSM-4R-12-18 provides full compatibility with the FR2249-SURFACEMOUNT across all critical parameters: 500mA DC switching current, 200V DC switching voltage, and 10W power rating. Both components maintain ROHS3 compliance and unlimited moisture sensitivity classification.

For AC applications, the MDSM-4R-12-18 presents a reduced AC switching current rating of 350mA compared to the FR2249-SURFACEMOUNT's 500mA, and a reduced AC switching voltage of 140V compared to 200V. AC-based designs must evaluate whether these reduced ratings remain acceptable for the intended application.

The operate range differential (FR2249-SURFACEMOUNT: 15–25AT; MDSM-4R-12-18: 12–18AT) indicates the substitute responds to a narrower magnetic field window. Applications requiring the full 15–25AT range must confirm that the 12–18AT range of the MDSM-4R-12-18 aligns with system magnetic field specifications.

Physical dimensions are comparable, with the MDSM-4R-12-18 measuring 0.760" overall length versus 0.770" for the FR2249-SURFACEMOUNT. The substitute exhibits a slightly increased height above board (0.112" versus 0.080"), which must be evaluated against PCB clearance constraints.

Frequently Asked Questions (FAQ)

Q: Can the MDSM-4R-12-18 directly replace the FR2249-SURFACEMOUNT in all applications?

A: Direct replacement is applicable for DC switching applications. AC applications require evaluation of the reduced AC current rating (350mA versus 500mA) and reduced AC voltage rating (140V versus 200V). The operate range difference (12–18AT versus 15–25AT) must be assessed against specific magnetic field requirements.

Q: What is the significance of the operate range difference between these parts?

A: The operate range defines the magnetic field strength (measured in Ampere-Turns, AT) required to actuate the reed switch. The FR2249-SURFACEMOUNT requires 15–25AT; the MDSM-4R-12-18 requires 12–18AT. Applications must confirm that the magnetic field generated by the actuating mechanism falls within the 12–18AT window of the substitute part.

Q: Are there packaging differences between these components?

A: The FR2249-SURFACEMOUNT packaging is listed as unspecified in the provided data. The MDSM-4R-12-18 is supplied in Tape & Reel (TR) format. Procurement and assembly processes must accommodate this packaging difference.

Q: How do the physical dimensions affect PCB layout compatibility?

A: Both components are surface mount with gull wing termination and comparable overall lengths (0.770" versus 0.760"). The MDSM-4R-12-18 exhibits a greater height above board (0.112" versus 0.080"), requiring verification that PCB clearance and component stacking constraints remain satisfied.

Q: What compliance certifications apply to both parts?

A: Both the FR2249-SURFACEMOUNT and MDSM-4R-12-18 are ROHS3 compliant, REACH unaffected, and classified as Moisture Sensitivity Level 1 (unlimited). Both carry ECCN classification EAR99 and HTSUS code 8536.50.9065.

Q: Why is the FR2249-SURFACEMOUNT classified as obsolete?

A: Obsolescence indicates the part is no longer manufactured by Coto Technology. The MDSM-4R-12-18 is an active product from Littelfuse Inc., ensuring ongoing availability and supply chain continuity for new designs and production requirements.