MARR-2-185 Equivalent & Substitute Parts

Part Overview

The MARR-2-185 is a glass body reed switch manufactured by Littelfuse Inc., configured as a SPST-NO (Single Pole Single Throw - Normally Open) device. This through-hole mounted component is rated for 750mA DC switching at 200V with a 10W power rating. The part is currently active in production with ROHS3 compliance and unlimited moisture sensitivity rating (MSL 1). Alternative components may be required due to inventory constraints, application-specific mounting requirements, or performance parameter optimization within acceptable electrical and mechanical tolerances.

Substiute Parts

MARR-2-185

Littelfuse Inc.In Stock: 670MARR-2-185 Datasheet

Current PartRFQ

KSK-1A35-1015

Standex-Meder ElectronicsIn Stock: 3690KSK-1A35-1015 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The KSK-1A35-1015 qualifies as an equivalent substitute based on the following critical parameters:

• Circuit Configuration: Both parts are SPST-NO reed switches with identical switching logic
• Voltage Rating: Both rated for 200V DC switching, meeting the primary electrical requirement
• Current Capacity: The substitute supports 1A (AC/DC), which exceeds the MARR-2-185 requirement of 750mA DC, providing operational margin
• Power Rating: The substitute is rated for 20W, exceeding the 10W requirement of the main part
• Temperature Range: The substitute operates across -40°C ~ 130°C, encompassing the main part's -40°C ~ 125°C range
• Compliance: Both parts are ROHS3 compliant with MSL 1 rating
• Type: Both are glass body reed switches with identical functional architecture

The primary difference is mounting type: the MARR-2-185 uses through-hole mounting while the KSK-1A35-1015 uses surface mount. This substitution is valid only when the application PCB layout can accommodate surface mount termination.

Parameter Comparison

Engineering Selection Recommendations

The KSK-1A35-1015 is electrically and functionally compatible with the MARR-2-185 for applications requiring SPST-NO reed switch operation at 200V DC with switching currents up to 750mA. Both parts maintain ROHS3 compliance and unlimited moisture sensitivity ratings, ensuring regulatory and environmental compatibility.

Selection between these parts should be based on:

• Mounting Architecture: Through-hole versus surface mount PCB design requirements
• Inventory Availability: Both parts are in active production with established stock levels
• Thermal Performance: The KSK-1A35-1015 supports operation to 130°C versus 125°C for the MARR-2-185
• Switching Speed: The KSK-1A35-1015 provides faster operate and release times (0.5 ms and 0.1 ms respectively)
• Power Margin: The KSK-1A35-1015 provides 20W rated power versus 10W, offering additional operational headroom

Frequently Asked Questions (FAQ)

Q: Can the KSK-1A35-1015 directly replace the MARR-2-185 on an existing PCB?

A: Direct PCB replacement is not possible due to different mounting types. The MARR-2-185 uses through-hole termination while the KSK-1A35-1015 uses surface mount. PCB layout modification is required.

Q: Are there electrical limitations when using the KSK-1A35-1015 as a substitute?

A: No. The KSK-1A35-1015 meets or exceeds all critical electrical parameters: 200V DC switching voltage, 1A switching current (exceeding the 750mA requirement), and 20W power rating (exceeding the 10W requirement).

Q: What is the impact of the different switching speeds?

A: The KSK-1A35-1015 operates faster (0.5 ms operate, 0.1 ms release) compared to the MARR-2-185 (0.75 ms operate, 0.3 ms release). This faster response may be beneficial for time-sensitive applications but does not create incompatibility.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the MARR-2-185 and KSK-1A35-1015 are ROHS3 compliant with MSL 1 (unlimited) moisture sensitivity ratings. Both carry EAR99 ECCN classification.

Q: What is the significance of the different current carry ratings?

A: The MARR-2-185 supports 1.5A DC carry while the KSK-1A35-1015 supports 1.25A AC/DC carry. For DC-only applications at or below 750mA switching current, both parts are adequate. The main part has a higher DC carry margin.

Q: Can the KSK-1A35-1015 operate across the full temperature range of the MARR-2-185?

A: Yes. The KSK-1A35-1015 operates from -40°C to 130°C, which encompasses the MARR-2-185 operating range of -40°C to 125°C.