RFS-25V331MI6#5 Equivalent & Substitute Parts

Part Overview

The RFS-25V331MI6#5 is a 330 µF, 25 V aluminum electrolytic capacitor in radial configuration manufactured by Elna America as part of the RFS/SILMIC II series. This component is rated for 1000 hours at 85°C and is designed for audio applications with a ripple current capability of 675 mA at 120 Hz.

The RFS-25V331MI6#5 carries an Obsolete product status. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure component availability, and support ongoing production or repair requirements for legacy systems utilizing this capacitor.

Substiute Parts

RFS-25V331MI6#5

Elna AmericaIn Stock: 877RFS-25V331MI6#5 Datasheet

Current PartRFQ

UFW2A331MHD

NichiconIn Stock: 1235UFW2A331MHD Datasheet

UpgradeRFQ

UKW2A331MHD

NichiconIn Stock: 1415UKW2A331MHD Datasheet

UpgradeRFQ

UFG1E331MPM

NichiconIn Stock: 2151UFG1E331MPM Datasheet

SimilarRFQ

UFW1E331MPD

NichiconIn Stock: 1130UFW1E331MPD Datasheet

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UKW1E331MPD

NichiconIn Stock: 1474UKW1E331MPD Datasheet

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UVR2A331MHD

NichiconIn Stock: 1446UVR2A331MHD Datasheet

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UKZ1E331MHM

NichiconIn Stock: 1239UKZ1E331MHM Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the RFS-25V331MI6#5 are classified into three categories based on electrical and mechanical compatibility:

Upgrade Substitutes (Higher Voltage Rating): Parts UFW2A331MHD and UKW2A331MHD maintain identical capacitance (330 µF) and tolerance (±20%), but feature a 100 V voltage rating instead of 25 V. These components are electrically compatible in applications where the original 25 V rating is sufficient, as higher-rated capacitors operate safely at lower voltages. Both upgrade substitutes provide extended lifetime (2000 Hrs @ 85°C) and improved ripple current performance. Physical dimensions remain identical: 0.492" diameter, 0.984" height, and 0.197" lead spacing.

Similar Substitutes (Same Voltage Rating, Different Physical Dimensions): Parts UFG1E331MPM, UFW1E331MPD, and UKW1E331MPD maintain the 25 V voltage rating and 330 µF capacitance with ±20% tolerance. These parts differ in physical size and performance characteristics. UFG1E331MPM features a smaller 0.394" diameter case with 0.866" height. UFW1E331MPD and UKW1E331MPD both use 0.394" diameter cases with reduced heights (0.551" and 0.492" respectively) and offer extended 2000-hour lifetime ratings. All maintain 0.197" lead spacing for PCB compatibility.

Parametric Equivalent (Same Voltage, Identical Physical Dimensions): Part UKZ1E331MHM provides direct parametric equivalence with the RFS-25V331MI6#5, matching all critical specifications: 330 µF capacitance, 25 V rating, ±20% tolerance, 1000-hour lifetime at 85°C, and identical physical dimensions (0.492" diameter, 0.984" height, 0.197" lead spacing).

Cross-Voltage Substitute (100 V Rating): Part UVR2A331MHD offers 100 V rating with identical physical dimensions to the main part and upgrade substitutes, providing an alternative from Nichicon's UVR series.

Substitution logic is based strictly on: capacitance value, voltage rating compatibility, tolerance, physical dimensions (diameter, height, lead spacing), mounting type, and compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement (Identical Specifications): UKZ1E331MHM is the parametric equivalent for the RFS-25V331MI6#5. Both components share identical electrical ratings (330 µF, 25 V, ±20% tolerance), thermal performance (1000 Hrs @ 85°C), and physical dimensions. This part is suitable for direct substitution in existing designs without PCB modification.

Upgrade Path (Higher Voltage Rating, Same Physical Footprint): UFW2A331MHD and UKW2A331MHD are recommended when component longevity and performance margin are priorities. Both maintain the identical physical form factor (0.492" diameter, 0.984" height, 0.197" lead spacing) and are electrically compatible in circuits designed for 25 V operation. The 100 V rating provides additional safety margin, and the extended 2000-hour lifetime at 85°C improves reliability compared to the original 1000-hour specification. UVR2A331MHD offers an alternative 100 V option with identical dimensions.

Space-Constrained Applications: UFW1E331MPD and UKW1E331MPD provide 25 V rated alternatives with reduced physical dimensions. UFW1E331MPD measures 0.394" diameter by 0.551" height, while UKW1E331MPD measures 0.394" diameter by 0.492" height. Both offer extended 2000-hour lifetime ratings. These parts require PCB layout verification to confirm lead spacing compatibility (0.197" maintained) and clearance around the smaller case diameter.

Compliance Verification: All substitute parts listed carry ROHS3 compliance certification, matching the original component's environmental compliance status. All parts are classified as REACH Unaffected and carry EAR99 export classification.

Product Status Consideration: The RFS-25V331MI6#5 and UKZ1E331MHM are both marked Obsolete. UFG1E331MPM is also Obsolete. UFW2A331MHD, UKW2A331MHD, UFW1E331MPD, UKW1E331MPD, and UVR2A331MHD are marked Not For New Designs. For new product development, consult with component suppliers for current-generation alternatives meeting equivalent electrical and mechanical specifications.

Frequently Asked Questions (FAQ)

Q: Can UFW2A331MHD or UKW2A331MHD be used as direct replacements for the RFS-25V331MI6#5?

A: Yes. Both parts maintain identical physical dimensions (0.492" diameter, 0.984" height, 0.197" lead spacing) and capacitance (330 µF). The 100 V voltage rating is compatible with circuits designed for 25 V operation. The primary differences are extended lifetime (2000 Hrs vs. 1000 Hrs @ 85°C) and improved ripple current performance. No PCB modification is required.

Q: What is the difference between the upgrade substitutes (UFW2A331MHD, UKW2A331MHD) and the parametric equivalent (UKZ1E331MHM)?

A: UKZ1E331MHM matches all specifications of the original part, including 25 V rating and 1000-hour lifetime. UFW2A331MHD and UKW2A331MHD feature 100 V ratings and 2000-hour lifetimes, providing enhanced performance margins. All three maintain identical physical dimensions and are electrically compatible in the original application.

Q: Can smaller-case alternatives (UFW1E331MPD, UKW1E331MPD) be used without PCB redesign?

A: Lead spacing remains constant at 0.197" (5.00 mm), so through-hole mounting holes align with standard PCB layouts. However, the reduced case diameter (0.394" vs. 0.492") requires verification of clearance around the component location. PCB layout review is necessary to confirm no interference with adjacent components or traces.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All substitute parts listed (UFW2A331MHD, UKW2A331MHD, UFG1E331MPM, UFW1E331MPD, UKW1E331MPD, UVR2A331MHD, UKZ1E331MHM) carry ROHS3 Compliant certification, matching the original RFS-25V331MI6#5 compliance status.

Q: What is the significance of "Not For New Designs" status on substitute parts?

A: This designation indicates the manufacturer is not recommending these parts for new product development. However, they remain valid for legacy system support, repair, and replacement applications. Verify component availability with suppliers before committing to production schedules.

Q: Which substitute offers the best reliability improvement?

A: UFW2A331MHD and UKW2A331MHD provide the most significant reliability enhancement, doubling the rated lifetime from 1000 hours to 2000 hours at 85°C while maintaining identical physical dimensions. These parts are suitable for applications requiring extended operational life.

Q: How do ripple current ratings affect substitution decisions?

A: The original RFS-25V331MI6#5 is rated for 675 mA ripple current at 120 Hz. UFW2A331MHD and UKW2A331MHD provide 750 mA at 120 Hz, offering improved ripple current handling. Smaller-case alternatives (UFW1E331MPD, UKW1E331MPD) provide 420 mA at 120 Hz. Verify the application's ripple current requirement before selecting a substitute with lower ripple current rating.