686LMB400M2BC Equivalent & Substitute Parts

Part Overview

The 686LMB400M2BC is a 68 µF, 400 V aluminum electrolytic capacitor manufactured by Cornell Dubilier / Illinois Capacitor in the LMB series. This radial, can-style snap-in capacitor is designed for general-purpose applications with a rated lifetime of 3000 hours at 105°C and an operating temperature range of -25°C to 105°C. The part is currently active in production and ROHS3 compliant.

Substitute parts are necessary when the original manufacturer discontinues production, when inventory is unavailable, or when design requirements call for enhanced performance characteristics such as higher voltage ratings or extended operational lifetime.

Substiute Parts

686LMB400M2BC

Cornell Dubilier / Illinois CapacitorIn Stock: 1098686LMB400M2BC Datasheet

Current PartRFQ

B43504A9686M000

EPCOS - TDK ElectronicsIn Stock: 6534B43504A9686M000 Datasheet

DirectRFQ

LGJ2G680MELZ20

NichiconIn Stock: 1447LGJ2G680MELZ20 Datasheet

DirectRFQ

450MXG68MEFCSN22X25

RubyconIn Stock: 6598450MXG68MEFCSN22X25 Datasheet

UpgradeRFQ

B43644A5686M000

EPCOS - TDK ElectronicsIn Stock: 3483B43644A5686M000 Datasheet

UpgradeRFQ

B43254A9686M000

EPCOS - TDK ElectronicsIn Stock: 1194B43254A9686M000 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 686LMB400M2BC are classified into three categories based on electrical and mechanical compatibility:

Direct Equivalents (400 V, 68 µF, 3000 Hrs @ 105°C): These parts maintain identical voltage rating, capacitance, and lifetime specifications. They are mechanically and electrically interchangeable with the main part.

• B43504A9686M000 (EPCOS - TDK Electronics, B43504 series)
• LGJ2G680MELZ20 (Nichicon, LGJ series)
• B43254A9686M000 (EPCOS - TDK Electronics, B43254 series)

Upgrade Equivalents (450 V, 68 µF): These parts provide higher voltage rating (450 V vs. 400 V) while maintaining 68 µF capacitance. They are suitable for applications requiring enhanced voltage margin or operating in higher voltage environments. Mechanical dimensions remain compatible.

• 450MXG68MEFCSN22X25 (Rubycon, MXG series, 3000 Hrs @ 105°C)
• B43644A5686M000 (EPCOS - TDK Electronics, B43644 series, 5000 Hrs @ 105°C)

Parametric Equivalent (400 V, 68 µF, 3000 Hrs @ 105°C): This part matches all primary electrical specifications and is mechanically compatible.

• B43254A9686M000 (EPCOS - TDK Electronics, B43254 series)

All substitute parts share the following critical parameters with the main part:

• Capacitance: 68 µF
• Tolerance: ±20%
• Package / Case: Radial, Can - Snap-In
• Mounting Type: Through Hole
• Lead Spacing: 0.394" (10.00 mm)
• Case Diameter: 0.866" (22.00 mm)
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 1 (Unlimited)

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Same Electrical and Mechanical Specifications):

Select LGJ2G680MELZ20 (Nichicon, LGJ series) as the primary direct substitute. This part is currently active in production, ROHS3 compliant, and maintains identical capacitance (68 µF), voltage rating (400 V), tolerance (±20%), and lifetime (3000 Hrs @ 105°C). Mechanical compatibility is confirmed with matching lead spacing (0.394", 10.00 mm) and radial snap-in package configuration. The part is suitable for new designs.

Alternative Direct Equivalent:

B43504A9686M000 (EPCOS - TDK Electronics, B43504 series) provides equivalent electrical specifications with improved ESR performance (1.29 Ohm @ 100Hz vs. 6.09509 Ohm @ 120Hz on the main part). However, this part is marked "Not For New Designs" and should be used only for legacy system maintenance or when existing inventory constraints require it.

For Enhanced Performance (Higher Voltage Rating):

Select B43644A5686M000 (EPCOS - TDK Electronics, B43644 series) when design requirements permit a higher voltage rating. This part offers 450 V rated voltage (vs. 400 V), extended lifetime of 5000 hours at 105°C (vs. 3000 hours), and superior ESR characteristics (1.43 Ohm @ 100Hz). It is active in production and ROHS3 compliant. Operating temperature range extends to -40°C, providing broader environmental compatibility. Mechanical dimensions are identical to the main part.

Alternative upgrade option: 450MXG68MEFCSN22X25 (Rubycon, MXG series) provides 450 V rating with 3000-hour lifetime and is currently active in production.

Avoid for New Designs:

Parts marked "Not For New Designs" (B43504A9686M000, B43254A9686M000) should not be selected for new product development. These are suitable only for field replacement or legacy system support.

Frequently Asked Questions (FAQ)

Q: Can I use a 450 V rated capacitor in place of a 400 V rated capacitor?

A: Yes. A higher voltage-rated capacitor is electrically compatible with a lower voltage application. The 450 V parts (450MXG68MEFCSN22X25, B43644A5686M000) can be used as direct replacements for the 400 V 686LMB400M2BC. This provides additional voltage margin and is a common engineering practice for reliability enhancement.

Q: What is the significance of ESR (Equivalent Series Resistance)?

A: ESR affects ripple current handling capability and heat generation. Lower ESR values indicate better performance under AC ripple conditions. The B43644A5686M000 (1.43 Ohm @ 100Hz) and B43504A9686M000 (1.29 Ohm @ 100Hz) have significantly lower ESR than the main part (6.09509 Ohm @ 120Hz), resulting in reduced heat dissipation and improved ripple current capacity.

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

A: All listed substitute parts maintain identical lead spacing (0.394", 10.00 mm) and radial snap-in package configuration. However, note that LGJ2G680MELZ20 has a reduced seated height of 0.866" (22.00 mm) compared to the main part's 1.063" (27.00 mm). Verify clearance in your specific PCB layout before substitution.

Q: What does "Not For New Designs" mean?

A: This designation indicates that the manufacturer has discontinued or is phasing out the product line. Parts with this status should not be selected for new product development. They are available for field replacement or legacy system support only. For new designs, select parts marked "Active" in product status.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts are ROHS3 compliant and carry identical environmental compliance certifications (REACH Unaffected, ECCN EAR99, HTSUS 8532.22.0040) as the main part.

Q: What is the difference between the 3000-hour and 5000-hour lifetime ratings?

A: Lifetime rating indicates the expected operational duration at maximum rated temperature (105°C) before capacitance degradation reaches specified limits. The B43644A5686M000 with 5000-hour rating provides extended service life compared to parts with 3000-hour ratings, making it suitable for applications requiring higher reliability or longer maintenance intervals.

Q: Can I substitute parts from different manufacturers?

A: Yes. All listed substitute parts are from different manufacturers (Nichicon, EPCOS - TDK Electronics, Rubycon) and are electrically and mechanically compatible with the original Cornell Dubilier / Illinois Capacitor part. Cross-manufacturer substitution is standard practice in electronics engineering when electrical specifications and mechanical dimensions match.