T491C685K025AS Equivalent & Substitute Parts

Part Overview

The T491C685K025AS is a 6.8 µF molded tantalum capacitor manufactured by KEMET, rated for 25 V operation in a 2312 (6032 Metric) surface mount package. This component is classified as obsolete, indicating that direct procurement from the original manufacturer may be limited or unavailable. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production or repair requirements for applications utilizing this capacitor specification.

Substiute Parts

T491C685K025AS

KEMETIn Stock: 1067T491C685K025AS Datasheet

Current PartRFQ

T491C685K025AT

KEMETIn Stock: 2830T491C685K025AT Datasheet

DirectRFQ

293D685X9025C2TE3

Vishay SpragueIn Stock: 1678293D685X9025C2TE3 Datasheet

SimilarRFQ

TAJC685K025H

KYOCERA AVXIn Stock: 1170TAJC685K025H Datasheet

SimilarRFQ

TPSC685K025H0500

KYOCERA AVXIn Stock: 1168TPSC685K025H0500 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the T491C685K025AS is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Capacitance: 6.8 µF
• Tolerance: ±10%
• Voltage Rating: 25 V
• Package / Case: 2312 (6032 Metric)
• Mounting Type: Surface Mount
• Operating Temperature Range: -55°C ~ 125°C
• Physical Dimensions: 0.236" L x 0.126" W (6.00mm x 3.20mm)

Allowable Variation Parameters:

• ESR (Equivalent Series Resistance): Variation permitted within component design specifications
• Packaging Format: Both cut tape and tape & reel formats are acceptable
• Manufacturer: Different manufacturers producing equivalent specifications

All identified substitute parts meet the mandatory matching parameters. Variations in ESR and packaging format do not affect functional compatibility in the application circuit, provided the electrical characteristics remain within the specified operating envelope.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: T491C685K025AT

The T491C685K025AT is the direct equivalent substitute for the T491C685K025AS. Both components are manufactured by KEMET within the T491 series and share identical electrical specifications, including 6.8 µF capacitance, ±10% tolerance, 25 V rating, and 1.9 Ohm ESR. The T491C685K025AT holds Active product status, ensuring ongoing availability and supply chain support. This part is ROHS3 compliant and carries a rated lifetime of 2000 hours at 125°C, providing enhanced reliability documentation compared to the obsolete main part.

Secondary Recommendations: 293D685X9025C2TE3, TAJC685K025H, TPSC685K025H0500

All four substitute parts meet the mandatory electrical and mechanical parameters. Selection among these alternatives should be based on:

• Availability and Lead Time: Verify current inventory status with component distributors
• Compliance Requirements: T491C685K025AT and 293D685X9025C2TE3 are ROHS3 compliant; TAJC685K025H and TPSC685K025H0500 are RoHS non-compliant
• ESR Characteristics: TPSC685K025H0500 offers significantly lower ESR (500 mOhm) compared to other options, suitable for applications requiring reduced impedance
• Packaging Format: Tape & Reel format (T491C685K025AT, 293D685X9025C2TE3, TPSC685K025H0500) is preferred for automated assembly; cut tape format (TAJC685K025H) is suitable for manual or low-volume operations

Frequently Asked Questions (FAQ)

Q: Can I use T491C685K025AT as a direct replacement for T491C685K025AS?

A: Yes. The T491C685K025AT is a direct equivalent substitute. Both parts share identical capacitance (6.8 µF), tolerance (±10%), voltage rating (25 V), package (2312), and ESR (1.9 Ohm). The primary difference is product status: T491C685K025AT is Active, while T491C685K025AS is Obsolete.

Q: What is the difference between cut tape and tape & reel packaging?

A: Cut tape packaging is supplied in individual strips suitable for manual handling and low-volume assembly. Tape & reel packaging is wound on reels for automated pick-and-place equipment. Both formats contain identical components; selection depends on assembly process requirements.

Q: Why does TPSC685K025H0500 have significantly lower ESR than other substitutes?

A: TPSC685K025H0500 belongs to the TPS series, which is engineered for low-ESR performance. The 500 mOhm ESR is within the allowable variation for this capacitance and voltage rating. Lower ESR reduces impedance and heat generation in high-frequency or high-current applications.

Q: Are all substitute parts RoHS compliant?

A: No. T491C685K025AT and 293D685X9025C2TE3 are ROHS3 compliant. TAJC685K025H and TPSC685K025H0500 are RoHS non-compliant. Compliance requirements depend on application and regulatory jurisdiction.

Q: Can I substitute parts with different ESR values?

A: Yes, provided the application circuit tolerates the ESR variation. ESR affects impedance and thermal characteristics. Verify that the substitute part's ESR does not degrade circuit performance, particularly in filtering, decoupling, or high-frequency applications.

Q: What is the physical height difference between substitutes?

A: All substitutes have a maximum seated height of 0.110" (2.80mm), except 293D685X9025C2TE3 at 0.110" (2.79mm). This 0.01mm difference is negligible for PCB assembly and does not affect mechanical compatibility.

Q: Are lifetime ratings provided for all substitute parts?

A: No. Only T491C685K025AT specifies a lifetime rating of 2000 hours at 125°C. Other substitutes do not provide lifetime data in the available specifications. Consult manufacturer datasheets for complete reliability information if lifetime rating is a critical design parameter.