T491B686K006AT Equivalent & Substitute Parts

Part Overview

The T491B686K006AT is a 68 µF molded tantalum capacitor manufactured by KEMET, rated for 6.3 V with ±10% tolerance. This component is designed for surface mount applications in the 1411 (3528 Metric) package format. The part is currently active in production with full RoHS3 compliance and unlimited moisture sensitivity level (MSL 1), making it suitable for general-purpose circuit applications requiring stable capacitance performance across the -55°C to 125°C operating temperature range.

Equivalent and substitute parts are necessary when the primary part number becomes unavailable, when alternative manufacturers offer improved lead times or inventory availability, or when design flexibility permits tolerance or ESR variations within acceptable circuit parameters.

Substiute Parts

T491B686K006AT

KEMETIn Stock: 3222T491B686K006AT Datasheet

Current PartRFQ

T491B686M006AT

KEMETIn Stock: 5259T491B686M006AT Datasheet

SimilarRFQ

293D686X96R3B2TE3

Vishay SpragueIn Stock: 5323293D686X96R3B2TE3 Datasheet

DirectRFQ

TAJB686K006RNJ

KYOCERA AVXIn Stock: 4800TAJB686K006RNJ Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the T491B686K006AT is determined by the following critical parameters:

Primary Matching Criteria:

• Capacitance: 68 µF (exact match required)
• Voltage Rating: 6.3 V (exact match required)
• Package / Case: 1411 (3528 Metric) (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Type: Molded Tantalum (exact match required)

Secondary Compatibility Parameters:

• Tolerance: ±10% or wider (±20% acceptable for applications with relaxed tolerance requirements)
• ESR (Equivalent Series Resistance): 900 mOhm or lower (lower ESR values are compatible)
• Operating Temperature Range: -55°C to 125°C minimum (matching or exceeding range acceptable)
• RoHS3 Compliance: Required for regulatory alignment
• Moisture Sensitivity Level: MSL 1 (Unlimited) preferred

The substitute parts listed below meet all primary matching criteria and maintain compatibility across secondary parameters.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts maintain active production status and full RoHS3 compliance, ensuring regulatory alignment and long-term availability.

T491B686M006AT (KEMET): This part differs only in tolerance specification (±20% versus ±10%). Selection is appropriate for applications where capacitance variation within ±20% is acceptable. Identical ESR, package dimensions, and thermal characteristics ensure direct functional compatibility.

293D686X96R3B2TE3 (Vishay Sprague): This part maintains ±10% tolerance matching the primary specification. The ESR specification of 1.8 Ohm is higher than the 900 mOhm baseline. Selection is appropriate for applications where higher ESR is tolerable. Height specification (2.11mm) is within acceptable tolerance of the primary part (2.10mm).

TAJB686K006RNJ (KYOCERA AVX): This part provides exact parameter alignment with the primary part across tolerance (±10%), ESR (900 mOhm), and all dimensional specifications. Selection is appropriate for direct replacement with no parameter trade-offs.

Frequently Asked Questions (FAQ)

Q: Can T491B686M006AT be used as a direct replacement for T491B686K006AT?

A: Yes, provided the circuit design permits ±20% capacitance tolerance. Both parts share identical voltage rating, ESR, package dimensions, and thermal operating range. The tolerance difference is the only specification variance.

Q: What is the significance of the ESR difference between 293D686X96R3B2TE3 and the primary part?

A: The 293D686X96R3B2TE3 has an ESR of 1.8 Ohm compared to 900 mOhm in the primary part. Higher ESR increases impedance at high frequencies and generates more heat under ripple current conditions. Selection requires circuit analysis to confirm acceptable performance in the specific application.

Q: Are all substitute parts available in the same package footprint?

A: Yes. All substitute parts use the 1411 (3528 Metric) package with identical length (0.138" / 3.50mm) and width (0.110" / 2.80mm). Height specifications are within 0.01mm tolerance, ensuring PCB layout compatibility.

Q: Do all substitute parts meet the same compliance requirements?

A: Yes. All parts listed are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity level, matching the primary part's regulatory and environmental specifications.

Q: Which substitute part provides the closest electrical match to T491B686K006AT?

A: TAJB686K006RNJ (KYOCERA AVX) provides exact parameter alignment across capacitance, tolerance, voltage rating, ESR, and thermal specifications, with no trade-offs in electrical performance.