DME2S18K Film Capacitor Equivalent & Substitute Parts

Part Overview

The DME2S18K is a 0.018 µF film capacitor manufactured by Cornell Dubilier Electronics (CDE) with a 250V DC voltage rating and ±10% tolerance. This component is classified as obsolete, which necessitates identification of active equivalent and substitute parts for ongoing design support and procurement. The DME2S18K features polyester metallized dielectric construction in a radial through-hole package suitable for general-purpose applications across industrial and commercial equipment.

Substiute Parts

DME2S18K

Cornell Dubilier Electronics (CDE)In Stock: 804DME2S18K Datasheet

Current PartRFQ

DME2S18K-F

Cornell Dubilier Electronics (CDE)In Stock: 5048DME2S18K-F Datasheet

DirectRFQ

DME4S18K-F

Cornell Dubilier Electronics (CDE)In Stock: 863DME4S18K-F Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete DME2S18K is determined by strict equivalence in the following critical parameters:

Primary Equivalence Criteria:

• Capacitance value: 0.018 µF (exact match required)
• Tolerance: ±10% (exact match required)
• Dielectric material: Polyester, Metallized (exact match required)
• Mounting type: Through Hole Radial (exact match required)
• Lead spacing: 0.295" (7.50mm) (exact match required)
• Operating temperature range: -55°C to 125°C (exact match required)

Secondary Compatibility Criteria:

• Voltage rating: Equal to or greater than the original specification
• Physical dimensions: Compatible with PCB layout constraints
• Termination type: PC Pins (exact match required)

The substitute parts are grouped into two categories based on voltage rating compatibility:

Group 1 - Direct Voltage Equivalent: DME2S18K-F maintains identical electrical specifications including 250V DC / 160V AC ratings while offering active product status and improved compliance.

Group 2 - Higher Voltage Rating: DME4S18K-F provides elevated voltage ratings (400V DC / 200V AC) while maintaining all other critical parameters, suitable for applications requiring higher voltage margin.

Parameter Comparison

Engineering Selection Recommendations

DME2S18K-F Selection Criteria:

The DME2S18K-F is the direct functional equivalent of the obsolete DME2S18K. This substitute maintains identical electrical and mechanical specifications including 250V DC / 160V AC voltage ratings, 0.018 µF capacitance, and ±10% tolerance. The primary advantage of DME2S18K-F is its active product status and ROHS3 compliance, addressing regulatory requirements for new designs and procurement. The identical physical dimensions and lead spacing ensure direct PCB compatibility without layout modifications. This part is suitable for applications where the original 250V DC specification is sufficient.

DME4S18K-F Selection Criteria:

The DME4S18K-F provides an alternative with elevated voltage ratings (400V DC / 200V AC) while maintaining all other critical electrical and mechanical parameters. This substitute is appropriate for applications requiring higher voltage margin or operating in higher voltage environments. The physical dimensions differ marginally in width (0.173" versus 0.177"), but lead spacing remains identical at 0.295" (7.50mm), ensuring PCB compatibility. DME4S18K-F also carries ROHS3 compliance and active product status. Selection of this part introduces no functional degradation in capacitance, tolerance, or temperature range.

Compliance Considerations:

Both substitute parts achieve ROHS3 compliance, addressing environmental and regulatory requirements absent in the obsolete DME2S18K. Both maintain EAR99 export classification and REACH unaffected status, preserving supply chain flexibility.

Frequently Asked Questions (FAQ)

Q: Can DME2S18K-F directly replace DME2S18K in existing designs?

A: Yes. The DME2S18K-F maintains identical electrical specifications (0.018 µF, ±10%, 250V DC / 160V AC), dielectric material (polyester metallized), operating temperature range (-55°C to 125°C), and physical dimensions (0.406" L x 0.177" W, 7.50mm lead spacing). No circuit modifications or PCB layout changes are required.

Q: What is the primary difference between DME2S18K-F and DME4S18K-F?

A: The DME4S18K-F provides higher voltage ratings (400V DC / 200V AC) compared to DME2S18K-F (250V DC / 160V AC). All other parameters including capacitance, tolerance, dielectric material, operating temperature, and lead spacing remain identical. The width dimension differs marginally (0.173" versus 0.177"), but lead spacing is unchanged.

Q: Can DME4S18K-F be used in applications designed for 250V DC operation?

A: Yes. The DME4S18K-F with 400V DC rating is electrically compatible with circuits specified for 250V DC operation. Higher voltage rating components operate safely at lower voltages. The identical capacitance (0.018 µF), tolerance (±10%), and operating temperature range (-55°C to 125°C) ensure functional equivalence.

Q: Are there any PCB layout considerations when substituting these parts?

A: Lead spacing remains constant at 0.295" (7.50mm) across all three parts, ensuring direct PCB compatibility. The DME4S18K-F has a marginally narrower width (0.173" versus 0.177"), which presents no compatibility issues. All parts are radial through-hole components with identical mounting type and termination (PC Pins).

Q: What is the significance of ROHS3 compliance in the substitute parts?

A: ROHS3 compliance indicates conformance to Restriction of Hazardous Substances regulations, addressing environmental and regulatory requirements for new designs and procurement in regulated markets. The obsolete DME2S18K is RoHS non-compliant, making the compliant substitutes necessary for applications subject to environmental regulations.

Q: Are DME2S18K-F and DME4S18K-F available in the same packaging as the original part?

A: Both substitute parts are supplied in bulk packaging, whereas the original DME2S18K was supplied in standard packaging. This represents a packaging format change rather than a component specification change. Bulk packaging does not affect component electrical or mechanical properties.

Q: Can these parts be used interchangeably in the same circuit?

A: DME2S18K-F and DME2S18K are fully interchangeable. DME4S18K-F is compatible with circuits designed for 250V DC operation due to its higher voltage rating, but should be selected only when the higher voltage specification provides design benefit or margin. All three parts share identical capacitance, tolerance, dielectric material, operating temperature, and lead spacing.