SLP121M400C3P3 Equivalent & Substitute Parts

Part Overview

The SLP121M400C3P3 is a 120 µF, 400 V aluminum electrolytic capacitor in a radial, can snap-in package manufactured by Cornell Dubilier Electronics (CDE). This component is currently active in production and is designed for general-purpose applications requiring reliable energy storage and filtering at elevated voltage levels. The identification of equivalent and substitute parts is necessary to ensure design flexibility, manage supply chain continuity, and accommodate sourcing constraints while maintaining electrical and mechanical compatibility.

Substiute Parts

SLP121M400C3P3

Cornell Dubilier Electronics (CDE)In Stock: 1072SLP121M400C3P3 Datasheet

Current PartRFQ

MAL215956121E3

Vishay Beyschlag/Draloric/BC ComponentsIn Stock: 1696MAL215956121E3 Datasheet

DirectRFQ

B43254B5127M000

EPCOS - TDK ElectronicsIn Stock: 878B43254B5127M000 Datasheet

UpgradeRFQ

LGX2W121MELA30

NichiconIn Stock: 1289LGX2W121MELA30 Datasheet

UpgradeRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of aluminum electrolytic capacitors is determined by the following critical electrical and mechanical parameters:

Primary Substitution Criteria:

• Capacitance value: 120 µF (exact match required)
• Tolerance: ±20% (must meet or exceed specification)
• Voltage rating: minimum 400 V (same or higher acceptable)
• Package type: Radial, Can - Snap-In (identical mechanical form)
• Lead spacing: 0.394" (10.00 mm) (exact match for PCB compatibility)
• Mounting type: Through Hole (fixed requirement)
• Physical dimensions: diameter and height (must fit allocated space)

Secondary Electrical Parameters:

• Operating temperature range: -25°C ~ 105°C (must support full operating window)
• ESR and ripple current ratings must be compatible with circuit requirements
• Lifetime rating impacts long-term reliability in the application

The three substitute parts identified below meet the primary mechanical and electrical criteria while offering different performance trade-offs in ESR characteristics and rated lifetime.

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalent - MAL215956121E3 (Vishay Beyschlag/Draloric/BC Components)

This substitute matches the SLP121M400C3P3 across all critical mechanical parameters and maintains 400 V voltage rating. The MAL215956121E3 offers superior electrical characteristics with lower ESR (1.6 Ohm @ 100 Hz versus 2.765 Ohm @ 120 Hz) and extended rated lifetime (5000 Hrs @ 105°C versus 3000 Hrs @ 105°C). Both components are rated for identical operating temperature range and ripple current at low frequency (760 mA @ 120 Hz). The part is active in production and ROHS3 compliant, making it suitable for new designs. Current inventory is 1646 pieces.

Upgrade Equivalent - LGX2W121MELA30 (Nichicon)

This substitute provides identical mechanical form factor and capacitance specification. The voltage rating is increased to 450 V, which is compatible with 400 V circuits. The LGX2W121MELA30 offers extended lifetime (5000 Hrs @ 105°C), matching the MAL215956121E3. It supports higher ripple current at low frequency (880 mA @ 120 Hz) and high frequency (1.2584 A @ 50 kHz). The part is active in production and ROHS3 compliant. Current inventory is 1227 pieces.

Alternative - B43254B5127M000 (EPCOS - TDK Electronics)

This substitute has identical capacitance, tolerance, and operating temperature range. The voltage rating is increased to 450 V. However, the product status is listed as "Not For New Designs," limiting its applicability to existing or legacy systems. Physical dimension shows 1.000" diameter (25.40 mm) versus 25.00 mm, which may present PCB layout constraints in space-restricted applications. Ripple current rating at low frequency (500 mA @ 120 Hz) is lower than the main part. Current inventory is 780 pieces.

Frequently Asked Questions (FAQ)

Q: Can MAL215956121E3 be used as a direct replacement for SLP121M400C3P3?

A: Yes. Both components have identical capacitance (120 µF), tolerance (±20%), voltage rating (400 V), lead spacing (10.00 mm), and radial snap-in package form. Physical dimensions are identical (25.00 mm diameter, 32.00 mm height seated), ensuring PCB compatibility without layout modifications.

Q: What is the difference between the 400 V and 450 V rated substitutes?

A: The main part SLP121M400C3P3 is rated for 400 V maximum. LGX2W121MELA30 and B43254B5127M000 are rated for 450 V. A 450 V-rated capacitor can be used in a 400 V application, as the higher voltage rating provides additional safety margin. However, the circuit operating voltage cannot exceed the component's rated voltage specification.

Q: Which substitute offers the best lifetime rating?

A: Both MAL215956121E3 and LGX2W121MELA30 are rated for 5000 hours at 105°C, compared to 3000 hours for the main part SLP121M400C3P3 and B43254B5127M000. Extended lifetime provides greater reliability for long-term operation in continuous-duty applications.

Q: Why is B43254B5127M000 marked as "Not For New Designs"?

A: Product status "Not For New Designs" indicates the manufacturer is discontinuing or has ceased active development of this component line. While existing inventory may be available, the manufacturer does not recommend using it for new circuit designs due to potential future supply discontinuation.

Q: Are there differences in ESR (Equivalent Series Resistance)?

A: The main part SLP121M400C3P3 has specified ESR of 2.765 Ohm @ 120 Hz. The MAL215956121E3 specifies lower ESR at 1.6 Ohm @ 100 Hz. Lower ESR reduces heat dissipation and improves high-frequency filtering performance. B43254B5127M000 and LGX2W121MELA30 do not provide ESR specifications in the available data.

Q: What is the physical dimension difference with B43254B5127M000?

A: The B43254B5127M000 has a slightly larger diameter of 1.000" (25.40 mm) compared to 0.984" (25.00 mm) for all other parts. This 0.40 mm difference may affect PCB mounting hole clearance in applications with tight mechanical tolerances or space constraints. Verify PCB layout spacing before substitution.

Q: Can these substitutes handle the same ripple current?

A: Ripple current handling varies among substitutes. At 120 Hz low frequency: SLP121M400C3P3 (750 mA), MAL215956121E3 (760 mA), B43254B5127M000 (500 mA), and LGX2W121MELA30 (880 mA). Circuit design must not exceed the component's rated ripple current specification. Higher ripple current capability allows the capacitor to operate with lower temperature rise in high-current applications.