T491B686K004AT Equivalent & Substitute Parts

Part Overview

The T491B686K004AT is a 68 µF molded tantalum capacitor manufactured by KEMET, rated for 4 V operation with ±10% tolerance. This component is part of the T491 series and is classified as Active product status. The device is housed in a 1411 (3528 Metric) surface mount package with a maximum seated height of 2.10 mm and an equivalent series resistance (ESR) of 1.8 Ohm.

Identifying equivalent and substitute parts is necessary to ensure design flexibility, manage supply chain continuity, and maintain component availability across manufacturing cycles. Substitute parts must satisfy identical electrical and mechanical parameters to ensure functional compatibility within the target application.

Substiute Parts

T491B686K004AT

KEMETIn Stock: 1068T491B686K004AT Datasheet

Current PartRFQ

TCKOG686BT

Cal-Chip Electronics, Inc.In Stock: 56904TCKOG686BT Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the T491B686K004AT are identified based on strict parametric equivalence. The following criteria determine substitution eligibility:

Critical Matching Parameters:

• Capacitance: 68 µF (exact match required)
• Voltage Rating: 4 V (exact match required)
• Tolerance: ±10% (exact match required)
• Package / Case: 1411 (3528 Metric) (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)
• Lifetime @ Temp.: 2000 Hrs @ 125°C (exact match required)
• Type: Molded Tantalum (exact match required)

Allowable Variation Parameters:

• ESR (Equivalent Series Resistance): Substitute parts may vary within acceptable engineering tolerances
• Manufacturer: Different manufacturers permitted if all critical parameters match

The TCKOG686BT from Cal-Chip Electronics, Inc. meets all critical matching parameters and qualifies as a parametric equivalent substitute.

Parameter Comparison

Engineering Selection Recommendations

Primary Part: T491B686K004AT (KEMET)

The T491B686K004AT is an Active product with full RoHS3 compliance and REACH Unaffected status. This component is suitable for applications requiring 68 µF capacitance at 4 V with general-purpose tantalum capacitor performance characteristics.

Substitute Part: TCKOG686BT (Cal-Chip Electronics, Inc.)

The TCKOG686BT is an Active product with RoHS compliance and REACH Unaffected status. This substitute meets all critical electrical and mechanical parameters. The ESR specification of 1.7 Ohm is marginally lower than the primary part's 1.8 Ohm, representing an allowable variation that does not compromise functional compatibility. Both components share identical capacitance, voltage rating, tolerance, package dimensions, and thermal characteristics.

Selection between these parts should be based on availability, lead time, and supply chain requirements. Both components are suitable for direct substitution in applications designed for the T491B686K004AT.

Frequently Asked Questions (FAQ)

Q: Can the TCKOG686BT replace the T491B686K004AT in existing designs?

A: Yes. The TCKOG686BT meets all critical electrical and mechanical parameters required for substitution. Both components feature identical capacitance (68 µF), voltage rating (4 V), tolerance (±10%), package type (1411 / 3528 Metric), and operating temperature range (-55°C ~ 125°C). The ESR difference (1.7 Ohm vs. 1.8 Ohm) is within acceptable engineering tolerances.

Q: Are there any compliance differences between these parts?

A: Both parts are Active products with equivalent regulatory compliance. The T491B686K004AT carries RoHS3 Compliant status, while the TCKOG686BT carries RoHS Compliant status. Both are REACH Unaffected and classified under ECCN EAR99. Compliance differences do not affect functional substitution.

Q: What is the significance of the ESR difference?

A: The ESR (Equivalent Series Resistance) difference of 0.1 Ohm (1.7 Ohm vs. 1.8 Ohm) is negligible for general-purpose applications. Both values fall within standard manufacturing tolerances for molded tantalum capacitors in this category and do not impact circuit performance in typical 4 V applications.

Q: Are the physical dimensions identical?

A: Yes. Both components share identical dimensions: 0.138" L x 0.110" W (3.50mm x 2.80mm) with a maximum seated height of 0.083" (2.10mm). Both use the 1411 (3528 Metric) package and Manufacturer Size Code B, ensuring identical PCB footprint compatibility.

Q: What is the Moisture Sensitivity Level (MSL) for these parts?

A: Both components carry MSL 1 (Unlimited) classification, indicating no moisture sensitivity restrictions. Standard handling and storage procedures apply without special moisture control requirements.

Q: Can these parts be used interchangeably in production?

A: Yes. Both parts are surface mount components with identical package specifications, operating temperature ranges, and lifetime ratings (2000 Hrs @ 125°C). They are suitable for interchangeable use in manufacturing processes designed for the T491B686K004AT.