Equivalent & Substitute Parts for T491B685K025AS

Part Overview

The T491B685K025AS is a 6.8 µF molded tantalum capacitor rated at 25 V in a 1411 (3528 Metric) surface mount package, manufactured by KEMET. 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

T491B685K025AS

KEMETIn Stock: 1165T491B685K025AS Datasheet

Current PartRFQ

T491B685K025AT

KEMETIn Stock: 9168T491B685K025AT Datasheet

DirectRFQ

TAJB685K025HNJ

KYOCERA AVXIn Stock: 861TAJB685K025HNJ Datasheet

DirectRFQ

293D685X9025B2TE3

Vishay SpragueIn Stock: 3370293D685X9025B2TE3 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the T491B685K025AS is determined by strict equivalence across the following critical parameters:

Electrical Parameters (Must Match):

• Capacitance: 6.8 µF
• Tolerance: ±10%
• Voltage Rating: 25 V
• Operating Temperature Range: -55°C to 125°C
• Moisture Sensitivity Level: 1 (Unlimited)

Mechanical Parameters (Must Match):

• Package / Case: 1411 (3528 Metric)
• Mounting Type: Surface Mount
• Physical Dimensions: 0.138" L x 0.110" W (3.50mm x 2.80mm)

Performance Parameters (Allowable Variation):

• ESR: 2.4 to 2.8 Ohm (minor variation acceptable within application tolerance)

All substitute parts listed meet these criteria. Variations in product status, RoHS compliance, and manufacturer lifetime ratings are noted but do not affect functional interchangeability in the specified application context.

Parameter Comparison

Engineering Selection Recommendations

T491B685K025AT (KEMET - Direct Substitute)

This part is the direct equivalent to the T491B685K025AS, differing only in packaging format (Tape & Reel versus bulk) and product status (Active versus Obsolete). All electrical and mechanical specifications are identical. This part carries ROHS3 compliance and demonstrates superior supply availability with 9102 units in stock. Selection of T491B685K025AT is appropriate for new designs and ongoing production requiring compliance with modern regulatory standards.

293D685X9025B2TE3 (Vishay Sprague - Functional Equivalent)

This part meets all critical electrical and mechanical parameters with a minor ESR variation (2.4 Ohm versus 2.8 Ohm), which represents improved performance characteristics. The part is ROHS3 compliant and REACH unaffected. Physical dimensions are equivalent with negligible height variation (2.11mm versus 2.10mm). Supply availability is strong at 3319 units in stock. This part is suitable for applications where lower ESR provides operational benefit.

TAJB685K025HNJ (KYOCERA AVX - Functional Equivalent)

This part satisfies all electrical and mechanical requirements with identical ESR specification. However, REACH status is listed as affected, requiring evaluation against specific regulatory requirements for the end application. Supply availability is lower at 761 units in stock. This part is suitable for applications where REACH compliance is not a constraint.

Frequently Asked Questions (FAQ)

Q: Can T491B685K025AT be used as a direct replacement for T491B685K025AS?

A: Yes. T491B685K025AT is functionally and mechanically identical to T491B685K025AS. The only differences are packaging format (Tape & Reel versus bulk) and product status (Active versus Obsolete). All electrical specifications, dimensions, and performance parameters are equivalent.

Q: What is the significance of the ESR difference in 293D685X9025B2TE3?

A: The 293D685X9025B2TE3 has an ESR of 2.4 Ohm compared to 2.8 Ohm in the main part. Lower ESR represents improved performance, reducing heat generation and voltage ripple in the application. This variation is within acceptable substitution parameters and may provide operational advantages.

Q: Are there any compliance differences between the substitute parts?

A: Yes. T491B685K025AT and 293D685X9025B2TE3 are ROHS3 compliant, while T491B685K025AS and TAJB685K025HNJ are RoHS non-compliant. Additionally, TAJB685K025HNJ has REACH affected status, while the other parts are REACH unaffected. These differences must be evaluated against specific application and regulatory requirements.

Q: Do all substitute parts use the same package and mounting type?

A: Yes. All substitute parts use the 1411 (3528 Metric) surface mount package with identical physical dimensions (0.138" L x 0.110" W / 3.50mm x 2.80mm) and maximum seated height of 0.083" (2.10mm to 2.11mm). Direct PCB footprint compatibility is maintained across all parts.

Q: What is the difference between bulk and Tape & Reel packaging?

A: The main part T491B685K025AS is supplied in bulk packaging, while substitute parts are supplied in Tape & Reel (TR) format. Tape & Reel packaging is standard for automated assembly processes and provides better component protection during handling and storage. Bulk packaging may require manual handling and reeling for automated placement equipment.

Q: Which substitute part offers the best supply availability?

A: T491B685K025AT offers the highest inventory level at 9102 units in stock, followed by 293D685X9025B2TE3 at 3319 units, and TAJB685K025HNJ at 761 units. For applications requiring immediate or large-volume procurement, T491B685K025AT is the preferred choice.

Q: Can these parts be used interchangeably in existing designs?

A: Yes, all substitute parts are mechanically and electrically interchangeable with the T491B685K025AS in the specified application context. PCB footprints, mounting requirements, and electrical performance are equivalent. No design modifications are required for substitution.