T491B686M006AT Equivalent & Substitute Parts

Part Overview

The T491B686M006AT is a 68 µF molded tantalum capacitor manufactured by KEMET, rated for 6.3 V with ±20% tolerance. This surface mount component operates across the temperature range of -55°C to 125°C with an equivalent series resistance (ESR) of 900 mOhm. The part is housed in a 1411 (3528 Metric) package and is classified as Active with ROHS3 compliance. Equivalent and substitute parts are identified to support design flexibility, inventory management, and supply chain continuity for applications requiring 68 µF tantalum capacitors at 6.3 V with compatible electrical and mechanical specifications.

Substiute Parts

T491B686M006AT

KEMETIn Stock: 5259T491B686M006AT Datasheet

Current PartRFQ

T494B686M006AT

KEMETIn Stock: 2112T494B686M006AT Datasheet

SimilarRFQ

293D686X06R3B2TE3

Vishay SpragueIn Stock: 7159293D686X06R3B2TE3 Datasheet

DirectRFQ

TAJB686M006RNJ

KYOCERA AVXIn Stock: 4182TAJB686M006RNJ Datasheet

DirectRFQ

TR3B686K010C0900

Vishay SpragueIn Stock: 1155TR3B686K010C0900 Datasheet

UpgradeRFQ

TPSB686M006R0500

KYOCERA AVXIn Stock: 16468TPSB686M006R0500 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the T491B686M006AT are classified based on strict adherence to the following electrical and mechanical parameters:

Primary Substitution Criteria:

• Capacitance: 68 µF (exact match required)
• Voltage Rating: 6.3 V (exact match required)
• Tolerance: ±20% (exact match required)
• Package / Case: 1411 (3528 Metric) (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Operating Temperature Range: -55°C to 125°C (exact match required)
• Type: Molded Tantalum (exact match required)

Secondary Variation Parameters (allowed to differ):

• ESR (Equivalent Series Resistance): May vary within acceptable operating parameters
• Manufacturer: Different manufacturers permitted
• Series designation: Different series permitted
• Lifetime @ Temp.: May vary or be unspecified

Upgrade Classification: Parts with higher voltage ratings (10 V vs. 6.3 V) or tighter tolerance (±10% vs. ±20%) are classified as upgrades and are electrically compatible for direct substitution in applications where the original specification permits.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitutes (Identical Electrical and Mechanical Specifications):

The following parts are direct substitutes for the T491B686M006AT:

• T494B686M006AT (KEMET): Identical specifications with reduced ESR (650 mOhm vs. 900 mOhm). Lower ESR provides improved performance in high-frequency applications and reduced thermal dissipation.
• 293D686X06R3B2TE3 (Vishay Sprague): Identical specifications with significantly reduced ESR (1.8 Ohm vs. 900 mOhm). Lowest ESR option among direct substitutes.
• TAJB686M006RNJ (KYOCERA AVX): Identical specifications with matching ESR (900 mOhm). Functionally equivalent alternative from different manufacturer.
• TPSB686M006R0500 (KYOCERA AVX): Identical specifications with reduced ESR (500 mOhm vs. 900 mOhm). Mid-range ESR option.

All direct substitutes maintain ROHS3 compliance, MSL 1 rating, and Active product status. All are available in Tape & Reel packaging.

Upgrade Option (Higher Voltage and Tighter Tolerance):

• TR3B686K010C0900 (Vishay Sprague): Rated for 10 V (vs. 6.3 V) with ±10% tolerance (vs. ±20%). This part is electrically compatible for direct substitution in applications where the original 6.3 V specification permits operation at higher voltage ratings. The tighter tolerance provides improved capacitance accuracy. Matching ESR (900 mOhm) ensures thermal performance equivalence.

Frequently Asked Questions (FAQ)

Q: Can T494B686M006AT be used as a direct replacement for T491B686M006AT?

A: Yes. Both parts share identical capacitance (68 µF), voltage rating (6.3 V), tolerance (±20%), package (1411 / 3528 Metric), and operating temperature range (-55°C to 125°C). The T494B686M006AT features lower ESR (650 mOhm vs. 900 mOhm), which is a performance improvement. Both are KEMET products with Active status and ROHS3 compliance.

Q: What is the difference between the Vishay Sprague 293D686X06R3B2TE3 and the KEMET T491B686M006AT?

A: Both parts are electrically and mechanically identical in capacitance, voltage, tolerance, package, and temperature range. The primary difference is manufacturer and ESR: the Vishay part has significantly lower ESR (1.8 Ohm vs. 900 mOhm), resulting in reduced impedance and improved high-frequency performance.

Q: Is the KYOCERA AVX TAJB686M006RNJ compatible with the T491B686M006AT?

A: Yes. The TAJB686M006RNJ is a direct substitute with identical electrical specifications (68 µF, 6.3 V, ±20%, 900 mOhm ESR) and mechanical specifications (1411 package, surface mount, -55°C to 125°C). It is ROHS3 compliant and Active status.

Q: Can the TR3B686K010C0900 replace the T491B686M006AT?

A: Yes, with design consideration. The TR3B686K010C0900 is rated for 10 V (higher than the 6.3 V original) with tighter tolerance (±10% vs. ±20%). This part is electrically compatible for direct substitution in circuits where the higher voltage rating is acceptable. The matching ESR (900 mOhm) ensures equivalent thermal performance.

Q: Why do substitute parts have different ESR values?

A: ESR variation reflects different manufacturing processes and internal construction among manufacturers. Lower ESR values (such as 500 mOhm or 1.8 Ohm) indicate improved performance characteristics, particularly in high-frequency applications and reduced heat generation. Selection depends on application requirements.

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

A: Yes. All listed substitute parts use the 1411 (3528 Metric) package with identical footprint dimensions (0.138" L x 0.110" W / 3.50 mm x 2.80 mm) and maximum seated height (0.083" / 2.10 mm). All are surface mount components compatible with standard PCB assembly processes.

Q: What is the significance of MSL 1 rating?

A: MSL 1 (Moisture Sensitivity Level 1) indicates unlimited shelf life without moisture bake-out requirements. All listed parts carry MSL 1 rating, eliminating moisture-related handling constraints during storage and assembly.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All substitute parts listed are ROHS3 compliant, meeting regulatory requirements for hazardous substance restrictions. All parts are also REACH unaffected and classified under ECCN EAR99.