T491B686M004AT Equivalent & Substitute Parts

Part Overview

The T491B686M004AT is a 68 µF molded tantalum capacitor manufactured by KEMET, rated for 4 V operation with ±20% capacitance tolerance. This surface mount component is housed in a 1411 (3528 Metric) package and features an equivalent series resistance (ESR) of 1.8 Ohm. The part is active in production status and RoHS3 compliant. Substitute parts are identified for applications requiring equivalent electrical and mechanical performance or where inventory availability necessitates alternative sourcing.

Substiute Parts

T491B686M004AT

KEMETIn Stock: 796T491B686M004AT Datasheet

Current PartRFQ

TCKOG686BT

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

Parametric EquivalentRFQ

TCMOG686BT

Cal-Chip Electronics, Inc.In Stock: 56791TCMOG686BT Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the T491B686M004AT are qualified based on the following critical parameters:

Electrical Parameters:

• Capacitance: 68 µF (exact match required)
• Voltage Rating: 4 V (exact match required)
• Type: Molded Tantalum (exact match required)
• Operating Temperature Range: -55°C ~ 125°C (exact match required)
• Lifetime @ Temperature: 2000 Hrs @ 125°C (exact match required)

Mechanical Parameters:

• Package / Case: 1411 (3528 Metric) (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Size / Dimension: 0.138" L x 0.110" W (3.50mm x 2.80mm) (exact match required)
• Height - Seated (Max): 0.083" (2.10mm) (exact match required)

Compliance Parameters:

• Moisture Sensitivity Level (MSL): 1 (Unlimited) (exact match required)
• REACH Status: REACH Unaffected (exact match required)

Substitute parts may vary in tolerance specification and ESR within acceptable ranges for the application, provided all other parameters remain equivalent.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts TCKOG686BT and TCMOG686BT are active production components from Cal-Chip Electronics, Inc., and are suitable for direct replacement of the T491B686M004AT in applications where the specified electrical and mechanical parameters are required.

TCKOG686BT features ±10% capacitance tolerance, which provides tighter tolerance control compared to the main part's ±20% specification. This substitute is appropriate for applications requiring improved capacitance accuracy.

TCMOG686BT maintains the ±20% capacitance tolerance matching the main part specification. This substitute is appropriate for applications with tolerance requirements identical to the original component.

Both substitutes feature ESR of 1.7 Ohm, which is lower than the main part's 1.8 Ohm specification, resulting in improved performance characteristics. All three parts are RoHS compliant and REACH unaffected, meeting regulatory requirements for industrial and commercial applications.

Frequently Asked Questions (FAQ)

Q: Can TCKOG686BT or TCMOG686BT be used as direct replacements for T491B686M004AT?

A: Yes. Both substitute parts match the critical electrical and mechanical parameters: 68 µF capacitance, 4 V voltage rating, molded tantalum type, 1411 (3528 Metric) package, surface mount configuration, identical physical dimensions, and equivalent operating temperature range and lifetime specifications.

Q: What is the difference between TCKOG686BT and TCMOG686BT?

A: The primary difference is capacitance tolerance. TCKOG686BT specifies ±10% tolerance, while TCMOG686BT specifies ±20% tolerance. Both parts are otherwise electrically and mechanically equivalent.

Q: Are there differences in ESR between the main part and substitutes?

A: Yes. The main part T491B686M004AT has an ESR of 1.8 Ohm, while both substitutes (TCKOG686BT and TCMOG686BT) have an ESR of 1.7 Ohm. The lower ESR of the substitutes represents improved performance characteristics.

Q: Do the substitute parts meet the same compliance standards?

A: Both substitute parts are RoHS compliant and REACH unaffected, meeting regulatory requirements equivalent to the main part. The main part carries RoHS3 certification, while the substitutes carry RoHS certification.

Q: Are the physical dimensions identical across all three parts?

A: Yes. All three parts 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). They are fully compatible for PCB layout and assembly processes.

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

A: All three parts carry MSL 1 (Unlimited), indicating no moisture sensitivity restrictions for storage, handling, or assembly.