MDCG-4-12-23 Equivalent & Substitute Parts

Part Overview

The MDCG-4-12-23 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 operates within a 12–23 AT (Ampere-Turn) range and is rated for 350mA AC / 500mA DC switching at 140V AC and 200V DC, with a maximum power dissipation of 10W. The part is currently in active production status with ROHS3 compliance and unlimited moisture sensitivity rating (MSL 1).

Substitute parts become necessary when addressing specific application requirements such as higher switching current capacity, increased voltage ratings, different mounting configurations, or enhanced operating temperature ranges while maintaining functional equivalence in SPST-NO reed switch topology.

Substiute Parts

MDCG-4-12-23

Littelfuse Inc.In Stock: 736MDCG-4-12-23 Datasheet

Current PartRFQ

KSK-1A35-1015

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

MFR RecommendedRFQ

KSK-1A66-1520

Standex-Meder ElectronicsIn Stock: 1882KSK-1A66-1520 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MDCG-4-12-23 is determined by the following critical parameters:

• Circuit topology: Must remain SPST-NO
• Switching current capacity: Must support at least 350mA AC / 500mA DC
• Voltage rating: Must support at least 140V AC / 200V DC
• Power dissipation: Must support at least 10W
• Compliance: Must maintain ROHS3 compliance and MSL 1 rating
• Product status: Must be active production

Two substitute parts meet these criteria:

KSK-1A35-1015 (Standex-Meder Electronics): Exceeds switching current (1A AC/DC) and voltage (200V AC/DC) specifications. Rated for 20W power dissipation. Surface mount configuration. Operating temperature range –40°C to 130°C.

KSK-1A66-1520 (Standex-Meder Electronics): Meets switching current (500mA AC/DC) and voltage (180V AC/DC) specifications. Rated for 10W power dissipation. Through-hole configuration matching original mounting type. Operating temperature range –40°C to 130°C.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts maintain active production status and ROHS3 compliance with unlimited moisture sensitivity ratings, ensuring regulatory and supply chain continuity.

KSK-1A35-1015 provides enhanced electrical performance with 1A switching capacity and 20W power rating, suitable for applications requiring higher current margins or increased power dissipation headroom. The surface-mount configuration requires PCB layout modification from the original through-hole design.

KSK-1A66-1520 maintains electrical specifications closely aligned with the MDCG-4-12-23 (500mA DC switching, 10W power rating) while preserving through-hole mounting compatibility. The 180V DC rating remains within acceptable margins for 200V DC applications. This part presents minimal integration risk for direct board-level substitution.

Both alternatives support the extended operating temperature range of –40°C to 130°C, exceeding the original specification of –40°C to 125°C.

Frequently Asked Questions (FAQ)

Q: Can KSK-1A35-1015 be used as a direct replacement for MDCG-4-12-23?

A: KSK-1A35-1015 meets all electrical substitution criteria (SPST-NO topology, 1A switching capacity exceeds 350mA/500mA requirement, 200V rating meets specification). However, the surface-mount termination style differs from the through-hole axial termination of the original part, requiring PCB redesign.

Q: Is KSK-1A66-1520 suitable for applications requiring 200V DC switching?

A: KSK-1A66-1520 is rated for 180V DC switching. Applications requiring 200V DC operation should verify that 180V rating provides adequate margin for the specific circuit design. The MDCG-4-12-23 specification of 200V DC is not matched by this substitute.

Q: What are the key differences in switching performance between these parts?

A: KSK-1A35-1015 and KSK-1A66-1520 both exhibit faster release times (0.1 ms versus 0.2 ms) and comparable operate times (0.5 ms versus 0.6 ms) relative to the MDCG-4-12-23. These timing differences may affect circuit behavior in time-sensitive applications.

Q: Are all three parts compliant with the same regulatory standards?

A: Yes. MDCG-4-12-23, KSK-1A35-1015, and KSK-1A66-1520 are all ROHS3 compliant, REACH unaffected, and carry MSL 1 (unlimited) moisture sensitivity ratings. All three are classified under ECCN EAR99 and HTSUS 8536.50.9065.

Q: Which substitute part requires the least integration effort?

A: KSK-1A66-1520 requires minimal integration effort due to matching through-hole mounting type and closely aligned electrical specifications (500mA DC, 10W power rating). PCB layout and component footprint remain compatible with the original design.