Equivalent & Substitute Parts for T491B686M006AS

Part Overview

The T491B686M006AS is a 68 µF molded tantalum capacitor rated at 6.3 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. The part operates across a temperature range of -55°C to 125°C and features a 900 mOhm equivalent series resistance (ESR). 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

T491B686M006AS

KEMETIn Stock: 1185T491B686M006AS Datasheet

Current PartRFQ

T491B686M006AT

KEMETIn Stock: 5259T491B686M006AT Datasheet

DirectRFQ

293D686X06R3B2TE3

Vishay SpragueIn Stock: 7159293D686X06R3B2TE3 Datasheet

SimilarRFQ

TPSB686M006H0500

KYOCERA AVXIn Stock: 1148TPSB686M006H0500 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the T491B686M006AS is determined by strict equivalence across the following critical 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)
• Type: Molded Tantalum (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)
• Moisture Sensitivity Level: 1 (Unlimited) (exact match required)

Secondary Consideration Parameters:

• ESR (Equivalent Series Resistance): Variations permitted within application tolerance
• Packaging Format: Tape & Reel (TR) or bulk packaging acceptable for equivalent functionality
• Product Status: Active status preferred for ongoing availability; obsolete status acceptable for legacy support
• RoHS Compliance: Noted for regulatory alignment but does not preclude substitution

All substitute parts listed meet the primary substitution criteria. Variations in ESR and product status are documented to enable informed selection based on application requirements and supply chain considerations.

Parameter Comparison

Engineering Selection Recommendations

T491B686M006AT (KEMET)

This part is the direct equivalent to the T491B686M006AS, differing only in packaging format (Tape & Reel versus bulk) and product status (Active versus Obsolete). The T491B686M006AT maintains identical electrical specifications, including 900 mOhm ESR, and is manufactured by the same supplier. This part carries ROHS3 compliance and includes a specified lifetime rating of 2000 hours at 125°C. Selection of this part is appropriate for applications requiring continuity with the original design specification and ongoing supply chain availability.

293D686X06R3B2TE3 (Vishay Sprague)

This substitute part meets all primary substitution criteria and is manufactured by Vishay Sprague under the TANTAMOUNT™ 293D series. The primary distinction is an elevated ESR of 1.8 Ohm compared to the 900 mOhm specification of the main part. This part carries ROHS3 compliance and is actively produced. Selection of this part is appropriate for applications where ESR variation is within acceptable design tolerance and cross-manufacturer sourcing is acceptable.

TPSB686M006H0500 (KYOCERA AVX)

This substitute part meets all primary substitution criteria and is manufactured by KYOCERA AVX under the TPS series. The primary distinction is a reduced ESR of 500 mOhm compared to the 900 mOhm specification of the main part. This part is actively produced and maintains RoHS non-compliant status consistent with the original part. Selection of this part is appropriate for applications where lower ESR is beneficial and cross-manufacturer sourcing is acceptable.

Frequently Asked Questions (FAQ)

Q: Can T491B686M006AT be used as a direct replacement for T491B686M006AS?

A: Yes. The T491B686M006AT is electrically and mechanically equivalent to the T491B686M006AS. Both parts share identical capacitance (68 µF), voltage rating (6.3 V), tolerance (±20%), package (1411 / 3528 Metric), ESR (900 mOhm), and operating temperature range (-55°C to 125°C). The primary difference is product status (Active versus Obsolete) and packaging format (Tape & Reel versus bulk). The T491B686M006AT is recommended for new procurement due to active production status.

Q: What is the significance of ESR variation among substitute parts?

A: Equivalent Series Resistance (ESR) affects the capacitor's impedance characteristics and heat dissipation under AC ripple current conditions. The main part specifies 900 mOhm ESR. The 293D686X06R3B2TE3 features 1.8 Ohm ESR (higher), while the TPSB686M006H0500 features 500 mOhm ESR (lower). Selection between these alternatives depends on circuit requirements for ripple current handling and thermal performance. Higher ESR increases heat generation; lower ESR reduces it.

Q: Are all substitute parts compatible with the original PCB layout?

A: Yes. All substitute parts share the identical 1411 (3528 Metric) package footprint with dimensions of 0.138" L x 0.110" W (3.50mm x 2.80mm) and maximum seated height of 0.083" (2.10mm). Physical compatibility with existing PCB designs is confirmed across all listed substitutes.

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

A: Tape & Reel (TR) packaging is a continuous strip format suitable for automated assembly processes. Bulk packaging refers to alternative formats such as trays or bags. Both formats contain identical components; packaging selection depends on manufacturing process requirements. The T491B686M006AT is available in Tape & Reel format, while the original T491B686M006AS packaging format is not specified.

Q: Does RoHS compliance affect substitution eligibility?

A: RoHS compliance status is noted for regulatory alignment but does not preclude substitution. The original T491B686M006AS is RoHS non-compliant. The T491B686M006AT and 293D686X06R3B2TE3 are ROHS3 compliant, while the TPSB686M006H0500 is RoHS non-compliant. Selection should align with applicable regulatory requirements for the end application.

Q: Can substitute parts with different ESR values affect circuit performance?

A: ESR variation can affect circuit performance in applications sensitive to impedance characteristics, such as high-frequency filtering or ripple current handling. The 293D686X06R3B2TE3 with 1.8 Ohm ESR exhibits higher impedance than the original 900 mOhm specification. The TPSB686M006H0500 with 500 mOhm ESR exhibits lower impedance. Circuit validation is necessary if ESR-dependent performance is critical to application function.

Q: Is the T491B series designation important for substitution?

A: The T491 series designation indicates the KEMET product family. The T491B686M006AT maintains this designation and is the direct equivalent within the KEMET product line. Cross-manufacturer substitutes (293D686X06R3B2TE3 from Vishay Sprague and TPSB686M006H0500 from KYOCERA AVX) belong to different manufacturer series but meet identical electrical and mechanical specifications for the 68 µF, 6.3 V, 1411 package category.