381LX331M400K042 Equivalent & Substitute Parts Reference

Part Overview

The 381LX331M400K042 is a 330 µF, 400 V aluminum electrolytic capacitor manufactured by Cornell Dubilier Electronics (CDE) in a radial, can snap-in package. This component is rated for 3000 hours at 105°C and is designed for general-purpose applications requiring through-hole mounting. The part is Active status and RoHS3 compliant.

Substitute parts are identified when equivalent or upgraded alternatives meet or exceed the electrical and mechanical specifications of the original component while maintaining compatibility with the same mounting footprint and package type. Upgrades may offer improved performance characteristics such as extended lifetime, reduced ESR, or higher voltage ratings.

Key Parameters

Parameter	Value
Capacitance	330 µF
Tolerance	±20%
Voltage - Rated	400 V
Lifetime @ Temperature	3000 Hrs @ 105°C
Operating Temperature Range	-25°C ~ 105°C
Polarization	Polar
Lead Spacing	0.394" (10.00 mm)
Size / Dimension	1.181" Dia (30.00 mm)
Height - Seated (Max)	1.654" (42.00 mm)
Mounting Type	Through Hole
Package / Case	Radial, Can - Snap-In
RoHS Status	RoHS3 Compliant
Moisture Sensitivity Level	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following criteria:

Parametric Equivalents maintain identical electrical specifications (330 µF capacitance, ±20% tolerance, 400 V rated voltage, 3000 Hrs @ 105°C lifetime) and mechanical compatibility (same package, lead spacing, and dimensions). These parts are direct replacements with no functional differences.

Upgrade Substitutes exceed the original specifications in one or more of the following areas:

Rated voltage increased from 400 V to 450 V
Lifetime extended from 3000 Hrs to 5000 Hrs @ 105°C
Equivalent Series Resistance (ESR) reduced or specified
Operating temperature range extended to -40°C minimum

All substitute parts maintain identical capacitance (330 µF), tolerance (±20%), lead spacing (10.00 mm), physical dimensions (1.181" Dia × 1.654" Height), mounting type (Through Hole), and package configuration (Radial, Can - Snap-In). All parts are RoHS3 compliant and suitable for general-purpose applications.

Parameter Comparison

Manufacturer Part Number	Manufacturer	Series	Capacitance	Voltage (V)	Tolerance	Lifetime @ 105°C	ESR	Operating Temp (°C)	Inventory (Pcs)
381LX331M400K042	Cornell Dubilier Electronics (CDE)	381LX	330 µF	400	±20%	3000 Hrs	—	-25 ~ 105	1,065
381LR331M400K042	Cornell Dubilier Electronics (CDE)	381LR	330 µF	400	±20%	3000 Hrs	402 mOhm @ 120 Hz	-25 ~ 105	2,177
450MXG330MEFCSN30X40	Rubycon	MXG	330 µF	450	±20%	3000 Hrs	—	-25 ~ 105	20,200
450VXH330MEFCSN30X40	Rubycon	VXH	330 µF	450	±20%	5000 Hrs	—	-25 ~ 105	100,400
B43508B5337M000	EPCOS - TDK Electronics	B43508	330 µF	450	±20%	3000 Hrs	370 mOhm @ 100 Hz	-40 ~ 105	139,300
B43644A5337M000	EPCOS - TDK Electronics	B43644	330 µF	450	±20%	5000 Hrs	90 mOhm @ 100 Hz	-40 ~ 105	2,767
ELXS451VSN331MR40S	Chemi-Con	LXS	330 µF	450	±20%	5000 Hrs	—	-25 ~ 105	1,292
LGN2W331MELB40	Nichicon	LGN	330 µF	450	±20%	3000 Hrs	—	-25 ~ 105	1,000,100
LQS2W331MELB40	Nichicon	LQS	330 µF	450	±20%	3000 Hrs	—	-25 ~ 105	1,000,100

Engineering Selection Recommendations

Parametric Equivalent Selection: The 381LR331M400K042 (Cornell Dubilier Electronics) is a parametric equivalent maintaining 400 V rating and 3000 Hrs @ 105°C lifetime. This part provides specified ESR of 402 mOhm @ 120 Hz and is suitable for direct replacement in applications where the original 381LX331M400K042 specifications are required. Both parts are RoHS3 compliant with MSL 1 rating.

Upgrade Selection - Extended Voltage Rating: Parts rated at 450 V (450MXG330MEFCSN30X40, 450VXH330MEFCSN30X40, B43508B5337M000, B43644A5337M000, ELXS451VSN331MR40S, LGN2W331MELB40, LQS2W331MELB40) provide increased voltage margin for applications operating near the 400 V specification limit. These upgrades maintain identical capacitance, tolerance, and mechanical compatibility while offering enhanced reliability through voltage derating.

Upgrade Selection - Extended Lifetime: Parts rated for 5000 Hrs @ 105°C (450VXH330MEFCSN30X40, B43644A5337M000, ELXS451VSN331MR40S) extend operational life by 67% compared to the original 3000 Hrs specification. These upgrades are suitable for applications requiring extended service intervals or operating in high-temperature environments.

Upgrade Selection - Reduced ESR: The B43644A5337M000 specifies 90 mOhm @ 100 Hz ESR, significantly lower than the 381LR331M400K042 at 402 mOhm @ 120 Hz. This upgrade reduces ripple current heating and improves performance in high-frequency switching applications. This part also extends operating temperature to -40°C minimum.

Compliance & Availability: All substitute parts are RoHS3 compliant and REACH unaffected. Inventory availability varies; LGN2W331MELB40 and LQS2W331MELB40 (Nichicon) offer highest stock levels at 1,000,100 units each.

Frequently Asked Questions (FAQ)

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

A: Yes. A 450 V rated capacitor is electrically compatible with a 400 V application. The higher voltage rating provides additional safety margin and does not affect circuit operation. All 450 V substitute parts maintain identical capacitance (330 µF), tolerance (±20%), and mechanical dimensions.

Q: What is the difference between parametric equivalents and upgrades?

A: Parametric equivalents (381LR331M400K042) maintain all original specifications including 400 V rating and 3000 Hrs @ 105°C lifetime. Upgrades exceed one or more specifications, such as increased voltage rating (450 V) or extended lifetime (5000 Hrs @ 105°C), while maintaining full mechanical and electrical compatibility.

Q: Are all substitute parts physically interchangeable?

A: Yes. All substitute parts share identical lead spacing (10.00 mm), physical dimensions (1.181" Dia × 1.654" Height), and snap-in package configuration. All are through-hole mounted components with the same footprint.

Q: Which substitute offers the best performance for high-ripple-current applications?

A: The B43644A5337M000 specifies the lowest ESR at 90 mOhm @ 100 Hz and provides 5000 Hrs @ 105°C lifetime. Reduced ESR minimizes resistive heating under ripple current stress. The 450VXH330MEFCSN30X40 also offers 5000 Hrs lifetime with extended availability.

Q: Do all substitutes maintain RoHS3 compliance?

A: Yes. All substitute parts listed are RoHS3 compliant. The B43644A5337M000 lists MSL as Not Applicable rather than MSL 1, indicating different moisture handling; however, this does not affect RoHS3 status.

Q: What is the advantage of extended lifetime (5000 Hrs vs. 3000 Hrs)?

A: Extended lifetime rating indicates the capacitor maintains specified performance characteristics for a longer operational period at 105°C. This is beneficial for applications with continuous operation or high ambient temperatures, reducing replacement frequency and improving system reliability.

Q: Can I substitute based on ESR specifications alone?

A: No. ESR is one performance characteristic but does not determine substitution eligibility. All substitutes must maintain identical capacitance (330 µF), tolerance (±20%), mechanical compatibility (lead spacing, dimensions, package type), and mounting configuration. ESR is a secondary selection criterion for optimizing performance in specific applications.

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