B43231B397M Equivalent & Substitute Parts

Part Overview

The B43231B397M is a 390 µF, 315 V aluminum electrolytic capacitor manufactured by EPCOS - TDK Electronics in a radial, can snap-in package. This component is rated for 2000 hours at 85°C and is designed for general-purpose applications requiring through-hole mounting. The part is currently active in production with ROHS3 compliance and unlimited moisture sensitivity rating.

Equivalent and substitute parts are identified when design requirements permit voltage uprating, extended operating temperature ranges, or improved lifetime specifications while maintaining the same capacitance, tolerance, physical dimensions, and mounting configuration.

Key Parameters

Parameter	B43231B397M
Capacitance	390 µF
Tolerance	±20%
Voltage - Rated	315 V
Lifetime @ Temperature	2000 Hrs @ 85°C
Operating Temperature Range	-25°C ~ 85°C
Lead Spacing	0.394" (10.00mm)
Size / Dimension	1.181" Dia (30.00mm)
Height - Seated (Max)	1.457" (37.00mm)
Mounting Type	Through Hole
Package / Case	Radial, Can - Snap-In
Polarization	Polar
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following criteria:

Mandatory Compatibility Parameters:

Capacitance: 390 µF (exact match required)
Tolerance: ±20% (exact match required)
Lead Spacing: 0.394" (10.00mm) (exact match required)
Size / Dimension: 1.181" Dia (30.00mm) (exact match required)
Mounting Type: Through Hole (exact match required)
Package / Case: Radial, Can - Snap-In (exact match required)
Polarization: Polar (exact match required)

Allowable Variation Parameters:

Voltage - Rated: May be equal to or greater than 315 V
Operating Temperature Range: May extend the upper limit beyond 85°C
Lifetime @ Temperature: May exceed 2000 Hrs @ 85°C
Height - Seated (Max): May vary within mechanical tolerance (37.00mm to 37.50mm acceptable)

All identified substitute parts maintain identical capacitance, tolerance, lead spacing, physical diameter, mounting type, and package configuration. Variations in voltage rating, operating temperature, and lifetime specifications represent design improvements or alternative manufacturer offerings suitable for applications where the original specification can be met or exceeded.

Parameter Comparison

Part Number	Manufacturer	Capacitance	Voltage - Rated	Tolerance	Lifetime @ Temp.	Operating Temp. Range	Lead Spacing	Size / Dimension	Height (Max)	RoHS Status
B43231B397M	EPCOS - TDK Electronics	390 µF	315 V	±20%	2000 Hrs @ 85°C	-25°C ~ 85°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.457" (37.00mm)	ROHS3 Compliant
LGU2F391MELB	Nichicon	390 µF	315 V	±20%	3000 Hrs @ 105°C	-25°C ~ 105°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.457" (37.00mm)	ROHS3 Compliant
380LQ391M400K032	Cornell Dubilier Electronics (CDE)	390 µF	400 V	±20%	2000 Hrs @ 85°C	-25°C ~ 85°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.457" (37.00mm)	ROHS3 Compliant
381LQ391M350K032	Cornell Dubilier Electronics (CDE)	390 µF	350 V	±20%	2000 Hrs @ 105°C	-25°C ~ 105°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.457" (37.00mm)	ROHS3 Compliant
400VXH390MEFCSN30X35	Rubycon	390 µF	400 V	±20%	5000 Hrs @ 105°C	-25°C ~ 105°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.457" (37.00mm)	ROHS3 Compliant
ESMQ401VSN391MR35S	Chemi-Con	390 µF	400 V	±20%	2000 Hrs @ 85°C	-25°C ~ 85°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.457" (37.00mm)	RoHS Compliant
ESMR451VSN391MR35S	Chemi-Con	390 µF	450 V	±20%	2000 Hrs @ 85°C	-25°C ~ 85°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.476" (37.50mm)	RoHS Compliant
LGG2G391MELB35	Nichicon	390 µF	400 V	±20%	2000 Hrs @ 105°C	-25°C ~ 105°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.457" (37.00mm)	ROHS3 Compliant
LGM2W391MELB35	Nichicon	390 µF	450 V	±20%	2000 Hrs @ 105°C	-25°C ~ 105°C	0.394" (10.00mm)	1.181" Dia (30.00mm)	1.476" (37.50mm)	ROHS3 Compliant

Engineering Selection Recommendations

Direct Equivalent (Same Voltage Rating): LGU2F391MELB (Nichicon) maintains the 315 V rating of the original B43231B397M while offering extended operating temperature range (-25°C ~ 105°C) and improved lifetime (3000 Hrs @ 105°C). Both parts are ROHS3 compliant with identical physical dimensions and lead spacing.

Voltage Uprated Substitutes (400 V Rating): 380LQ391M400K032 (CDE), ESMQ401VSN391MR35S (Chemi-Con), LGG2G391MELB35 (Nichicon), and 400VXH390MEFCSN30X35 (Rubycon) provide 400 V rated capacity. The 400VXH390MEFCSN30X35 offers the longest lifetime specification at 5000 Hrs @ 105°C with extended operating temperature range. LGG2G391MELB35 combines 400 V rating with 2000 Hrs @ 105°C and ROHS3 compliance.

Voltage Uprated Substitutes (450 V Rating): LGM2W391MELB35 (Nichicon) and ESMR451VSN391MR35S (Chemi-Con) provide 450 V rated capacity. LGM2W391MELB35 offers ROHS3 compliance and extended operating temperature range (-25°C ~ 105°C). Height variation to 1.476" (37.50mm) must be verified for mechanical clearance in the application.

Voltage Uprated Substitutes (350 V Rating): 381LQ391M350K032 (CDE) provides 350 V rated capacity with 2000 Hrs @ 105°C lifetime and extended operating temperature range (-25°C ~ 105°C). This option is suitable when voltage margin above 315 V is required but 400 V or higher is not necessary.

All substitute parts maintain ROHS3 or RoHS compliance status and are active products in current production.

Frequently Asked Questions (FAQ)

Q: Can I use a higher voltage rated capacitor as a substitute for the B43231B397M? A: Yes. The B43231B397M is rated for 315 V. Any substitute with equal or higher voltage rating (350 V, 400 V, or 450 V) is electrically compatible. Higher voltage ratings provide additional safety margin in the circuit.

Q: What is the difference between the LGU2F391MELB and the original B43231B397M? A: Both maintain 315 V rating and identical physical dimensions. The LGU2F391MELB extends the operating temperature range to 105°C and increases lifetime to 3000 Hrs @ 105°C compared to 2000 Hrs @ 85°C. Both are ROHS3 compliant.

Q: Why do some substitutes have different height specifications? A: The ESMR451VSN391MR35S and LGM2W391MELB35 have a maximum seated height of 1.476" (37.50mm) versus 1.457" (37.00mm) for the original part. This 0.019" (0.50mm) difference must be verified for mechanical clearance in the application before substitution.

Q: Are all substitute parts ROHS3 compliant? A: Most substitutes are ROHS3 compliant. The ESMQ401VSN391MR35S and ESMR451VSN391MR35S are RoHS compliant. Verify specific compliance requirements for your application.

Q: What does "Lifetime @ Temperature" mean? A: This specification indicates the expected operational life of the capacitor at a specific temperature. For example, 2000 Hrs @ 85°C means the capacitor is rated for 2000 hours of operation at 85°C. Higher lifetime values indicate longer expected service life under those conditions.

Q: Can I substitute a 400 V rated capacitor in a circuit designed for 315 V? A: Yes. A 400 V rated capacitor can be used in a 315 V circuit. The higher voltage rating provides additional safety margin and does not affect circuit operation. The capacitance value remains 390 µF in all cases.

Q: What is the significance of the lead spacing specification? A: Lead spacing (0.394" or 10.00mm) determines the physical distance between the two connection points on the PCB. All listed substitutes maintain identical lead spacing, ensuring direct mechanical compatibility with existing PCB layouts.

Q: Do all substitutes have the same ripple current rating? A: No. Ripple current ratings vary among manufacturers. Verify the ripple current specification for your specific application requirements, as this parameter is not uniform across all substitute parts.

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