MDCG-4-27-38 Equivalent & Substitute Parts

Part Overview

The MDCG-4-27-38 is a glass body reed switch manufactured by Littelfuse Inc., configured as a single-pole single-throw normally open (SPST-NO) device. This component is designed for low-power switching applications requiring reliable contact closure in the presence of a magnetic field. The part is currently in active production status with 819 units available in inventory. Alternative equivalent parts may be required due to supply constraints, lead time considerations, or specific application requirements within the allowed electrical and mechanical parameter ranges.

Substiute Parts

MDCG-4-27-38

Littelfuse Inc.In Stock: 907MDCG-4-27-38 Datasheet

Current PartRFQ

KSK-1A66/3-2030

Standex-Meder ElectronicsIn Stock: 1307KSK-1A66/3-2030 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MDCG-4-27-38 is permissible with parts that maintain functional equivalence within the following critical parameters:

Circuit Configuration: Both the main part and substitute must be SPST-NO to ensure identical switching behavior.

Mounting and Termination: Through hole mounting with axial termination is required for mechanical compatibility with existing PCB layouts.

Electrical Performance: The substitute must support the application's voltage and current requirements. The MDCG-4-27-38 operates at 140 V AC / 200 V DC with switching currents of 350 mA (AC) and 500 mA (DC). A substitute part must meet or exceed these electrical specifications.

Power Rating: The 10 W rated power must be maintained or exceeded.

Environmental Compliance: Both parts must maintain ROHS3 compliance and unlimited moisture sensitivity level (MSL 1) for equivalent reliability in production and storage environments.

Operating Temperature: The substitute must support the -40°C to 125°C operating range or a broader range that encompasses this specification.

The KSK-1A66/3-2030 from Standex-Meder Electronics meets these substitution criteria with enhanced electrical performance characteristics.

Parameter Comparison

Engineering Selection Recommendations

Both the MDCG-4-27-38 and KSK-1A66/3-2030 are active production components with full ROHS3 compliance and unlimited moisture sensitivity ratings, ensuring equivalent environmental reliability and regulatory standing.

The KSK-1A66/3-2030 provides enhanced AC voltage switching capability at 200 V compared to the MDCG-4-27-38 at 140 V AC, while maintaining identical DC voltage performance at 200 V. The substitute part supports 500 mA switching current in both AC and DC modes, exceeding the MDCG-4-27-38 DC specification of 500 mA but providing equivalent AC performance at 350 mA.

Both parts share identical 10 W power ratings, through hole mounting, and axial termination, ensuring direct mechanical and electrical compatibility in existing circuit designs. The operating temperature range of the KSK-1A66/3-2030 extends to 130°C, providing a 5°C margin above the MDCG-4-27-38 specification.

Selection between these parts should be based on specific application voltage and current requirements within the provided electrical specifications and compliance certifications.

Frequently Asked Questions (FAQ)

Q: Can the KSK-1A66/3-2030 be used as a direct replacement for the MDCG-4-27-38?

A: Yes, within the constraints of your application's voltage and current requirements. Both parts are SPST-NO glass body reed switches with identical 10 W power ratings, through hole mounting, and axial termination. Verify that your circuit operates within the electrical specifications of the substitute part.

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

A: The MDCG-4-27-38 operates at 27 ~ 38 AT (Ampere-Turns), while the KSK-1A66/3-2030 operates at 20 ~ 30 AT. The lower operate range of the substitute may result in activation at lower magnetic field strengths. Confirm that your magnetic field source is compatible with the substitute part's activation threshold.

Q: Are there differences in switching speed?

A: The MDCG-4-27-38 has an operate time of 0.6 ms and release time of 0.2 ms. The KSK-1A66/3-2030 has an operate time of 0.7 ms and release time of 0.05 ms. For timing-critical applications, these differences should be evaluated against your circuit requirements.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the MDCG-4-27-38 and KSK-1A66/3-2030 are ROHS3 compliant with MSL 1 (unlimited) moisture sensitivity ratings, ensuring equivalent environmental and regulatory compliance.

Q: What is the maximum current each part can carry continuously?

A: The MDCG-4-27-38 carries 1.2 A DC continuously. The KSK-1A66/3-2030 carries 1 A in both AC and DC modes. Ensure your application's continuous current requirement does not exceed these ratings.

Q: Are the physical dimensions compatible?

A: Both parts use through hole mounting with axial termination. The MDCG-4-27-38 has an overall length of 1.590" (40.39 mm), while the KSK-1A66/3-2030 is 1.744" (44.30 mm). Verify that your PCB layout accommodates the slightly longer substitute part.