T491B686K006AT2478 Equivalent & Substitute Parts

Part Overview

The T491B686K006AT2478 is a 68 µF molded tantalum capacitor manufactured by KEMET, rated for 6.3 V operation in a 1411 (3528 Metric) surface mount package. This component is classified as Active product status and is designed for general-purpose applications requiring stable capacitance and low equivalent series resistance in compact form factors.

Substitute parts become necessary when the primary manufacturer part experiences extended lead times, inventory constraints, or when design flexibility permits equivalent alternatives from qualified manufacturers. The identification of suitable substitutes requires strict alignment of electrical specifications, mechanical dimensions, and compliance certifications to ensure functional interchangeability without design modification.

Substiute Parts

T491B686K006AT2478

KEMETIn Stock: 856T491B686K006AT2478 Datasheet

Current PartRFQ

TCKOJ686BT

Cal-Chip Electronics, Inc.In Stock: 56871TCKOJ686BT Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the T491B686K006AT2478 is determined by strict equivalence across the following critical parameters:

Electrical Specifications:

• Capacitance value: 68 µF (exact match required)
• Tolerance: ±10% (identical tolerance band)
• Rated voltage: 6.3 V (minimum voltage rating must equal or exceed this value)
• ESR: 900 mOhm (equivalent series resistance must match)
• Operating temperature range: -55°C to 125°C (full range coverage required)
• Lifetime rating: 2000 Hrs @ 125°C (minimum endurance specification)

Mechanical Specifications:

• Package type: 1411 (3528 Metric) surface mount (exact package match required)
• Physical dimensions: 0.138" L x 0.110" W (3.50mm x 2.80mm) (exact match required)
• Maximum seated height: 0.083" (2.10mm) (exact match required)
• Mounting type: Surface Mount (identical mounting technology)

Compliance & Regulatory:

• RoHS3 Compliance (mandatory for equivalent substitution)
• Moisture Sensitivity Level: 1 (Unlimited) (identical MSL classification)
• REACH Status: REACH Unaffected (regulatory equivalence)

Substitute parts must satisfy all parameters listed above without exception. Partial matches or parameter relaxation do not constitute valid substitution.

Parameter Comparison

Engineering Selection Recommendations

Primary Part: T491B686K006AT2478 (KEMET)

The T491B686K006AT2478 maintains Active product status with full ROHS3 compliance and REACH Unaffected regulatory standing. This part is suitable for applications where KEMET supply chain availability and established manufacturing history are preferred.

Substitute Part: TCKOJ686BT (Cal-Chip Electronics, Inc.)

The TCKOJ686BT from Cal-Chip Electronics, Inc. provides complete electrical and mechanical equivalence to the primary part. All critical parameters—capacitance, voltage rating, ESR, temperature range, lifetime rating, package dimensions, and compliance certifications—are identical. This substitute is suitable for applications where Cal-Chip Electronics supply chain availability is advantageous or where design flexibility permits manufacturer substitution.

Both parts carry identical compliance certifications (ROHS3 Compliant, REACH Unaffected) and identical moisture sensitivity classification (MSL 1 - Unlimited), confirming regulatory and handling equivalence.

Selection between these parts should be based on supply chain availability, lead time requirements, and procurement cost considerations. No electrical or mechanical design modifications are required when substituting between these parts.

Frequently Asked Questions (FAQ)

Q: Can the TCKOJ686BT be used as a direct replacement for the T491B686K006AT2478 without PCB layout modifications?

A: Yes. Both parts share identical package specifications (1411 / 3528 Metric), physical dimensions (0.138" L x 0.110" W / 3.50mm x 2.80mm), and maximum seated height (0.083" / 2.10mm). No PCB layout changes are required for substitution.

Q: Are the electrical performance characteristics identical between these two parts?

A: Yes. Both parts specify 68 µF capacitance at ±10% tolerance, 6.3 V rated voltage, 900 mOhm ESR, -55°C to 125°C operating temperature range, and 2000 Hrs lifetime at 125°C. Electrical performance is equivalent.

Q: Do both parts meet the same compliance and regulatory requirements?

A: Yes. Both the T491B686K006AT2478 and TCKOJ686BT are ROHS3 Compliant, REACH Unaffected, and classified as Moisture Sensitivity Level 1 (Unlimited). Regulatory and compliance standing is identical.

Q: What is the difference between these two parts?

A: The parts differ only in manufacturer (KEMET versus Cal-Chip Electronics, Inc.) and manufacturer-specific part numbering. All electrical specifications, mechanical dimensions, package type, and compliance certifications are identical.

Q: Is the TCKOJ686BT available in the same packaging format?

A: Yes. The TCKOJ686BT is supplied in Tape & Reel (TR) packaging, identical to the T491B686K006AT2478, suitable for automated assembly processes.

Q: Can I mix these parts in the same production batch?

A: Yes. Both parts meet identical electrical, mechanical, and compliance specifications. Mixing is permissible from a functional and regulatory standpoint. Procurement and inventory management practices should determine mixing strategy.

Q: What should I verify before implementing a substitution?

A: Confirm that your application requirements align with the specified parameters: 68 µF capacitance, 6.3 V minimum voltage rating, 900 mOhm ESR tolerance, -55°C to 125°C operating range, and 1411 (3528 Metric) surface mount package. If your application requires different specifications, these parts are not suitable substitutes.