LF-305 Line Filter Equivalent & Substitute Parts

Part Overview

The KEMET LF-305 is a three-phase delta EMC/EMI line filter rated for 250VDC/VAC at 5A with chassis mount configuration and threaded post (M4) termination. This component is designated as Last Time Buy, indicating discontinued production status. The LF-305 serves general-purpose filtering applications in industrial and power distribution systems requiring compact, two-stage filtration architecture.

Due to Last Time Buy status, identification of equivalent substitute components is necessary for design continuity and procurement planning. Substitute parts must maintain functional equivalence within the constraints of electrical ratings, mechanical mounting, and termination compatibility.

Substiute Parts

LF-305

KEMETIn Stock: 1113LF-305 Datasheet

Current PartRFQ

GTX-3300-Y103

KEMETIn Stock: 1179GTX-3300-Y103 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution analysis for the LF-305 is constrained by the following critical parameters:

Electrical Compatibility Requirements:

• Filter topology must be three-phase delta configuration
• Two-stage filtration architecture must be maintained
• Voltage rating must equal or exceed 250VDC/250VAC
• Current rating must equal or exceed 5A

Mechanical Compatibility Requirements:

• Mounting type must be chassis mount
• Termination style must accommodate M4 threaded post connections or equivalent mechanical interface

Regulatory & Environmental Requirements:

• RoHS3 compliance required
• Operating temperature range must encompass -20°C to 55°C minimum

The substitute part GTX-3300-Y103 is identified as a manufacturer-recommended alternative. However, this part exhibits significant parameter deviations that require engineering evaluation for specific application contexts.

Parameter Comparison

Engineering Selection Recommendations

GTX-3300-Y103 Substitution Considerations:

The GTX-3300-Y103 provides electrical parameter coverage exceeding LF-305 specifications in voltage (500V vs. 250V) and current capacity (30A vs. 5A). Both components share identical filter topology (three-phase delta), configuration (two stage), and mounting methodology (chassis mount).

Critical Incompatibility:

The termination style differs fundamentally: LF-305 uses threaded post (M4) connections, while GTX-3300-Y103 employs terminal block termination. This mechanical incompatibility requires circuit board redesign or custom interconnect solutions.

Regulatory Alignment:

Both components maintain ROHS3 compliance. GTX-3300-Y103 carries cUL and UL certifications, providing enhanced regulatory coverage compared to the LF-305 (certification data not provided).

Application Scope:

GTX-3300-Y103 is specified for inverters and power drive systems, representing a higher-performance product category than the general-purpose LF-305 classification.

Substitution Feasibility:

Direct mechanical substitution is not possible without termination interface modification. Electrical substitution is feasible only in applications where terminal block termination can be accommodated and where the elevated voltage/current ratings do not introduce design complications.

Frequently Asked Questions (FAQ)

Q: Can GTX-3300-Y103 directly replace LF-305 in existing designs?

A: No. The termination style incompatibility (threaded post M4 vs. terminal block) prevents direct mechanical substitution. Circuit board modifications or custom interconnect solutions are required.

Q: Are the electrical ratings of GTX-3300-Y103 compatible with LF-305 applications?

A: GTX-3300-Y103 exceeds LF-305 electrical specifications (500V DC vs. 250V, 30A vs. 5A). Electrical compatibility exists, but the higher ratings may introduce unnecessary cost and board space considerations for applications requiring only 250V/5A performance.

Q: What is the significance of the Last Time Buy status for LF-305?

A: Last Time Buy designation indicates KEMET has discontinued production of the LF-305. Existing inventory is limited to 1085 pieces. New designs should transition to active product alternatives such as GTX-3300-Y103 to ensure long-term supply chain continuity.

Q: Do both components meet the same regulatory standards?

A: Both LF-305 and GTX-3300-Y103 are ROHS3 compliant. GTX-3300-Y103 carries additional cUL and UL certifications. Regulatory requirements for specific applications must be evaluated independently.

Q: What is the operating temperature compatibility between these components?

A: Both components operate within overlapping temperature ranges. GTX-3300-Y103 extends the lower limit to -25°C (vs. -20°C for LF-305), providing broader environmental coverage.

Q: Are there packaging differences between LF-305 and GTX-3300-Y103?

A: Yes. LF-305 is supplied in box packaging (1085 pieces in stock), while GTX-3300-Y103 is supplied in bulk packaging (1083 pieces in stock). Packaging selection depends on procurement and inventory management requirements.

Q: What applications is GTX-3300-Y103 designed for?

A: GTX-3300-Y103 is specified for inverters and power drive systems, representing a specialized application category. LF-305 serves general-purpose filtering applications. Application-specific performance requirements must be evaluated before substitution.