EF3L90CG400H

The EF3L90CG400H is a metallized polypropylene (PP) film capacitor from Panasonic’s EF series, designed for high-voltage DC-link, power factor correction, and general power supply filtering applications in industrial and consumer power electronics. The EF series is part of Panasonic’s comprehensive film capacitor portfolio, known for reliable performance, self-healing capability, and long operational life. Metallized polypropylene film capacitors use a thin polypropylene plastic film as the dielectric, vacuum-coated with a thin layer of metal (typically aluminum or zinc/aluminum alloy) on both sides to form the electrodes. This metallized film construction offers the self-healing property: if a localized dielectric breakdown occurs (from a voltage transient or defect), the resulting arc evaporates the thin metal electrode around the breakdown point, isolating the fault and allowing the capacitor to continue functioning — a significant reliability advantage over foil-type film capacitors. The EF3L90CG400H provides 40 microfarads of capacitance at a 400 V DC rating, with a tight ±5% capacitance tolerance (G class) for applications requiring precise capacitance values. The non-inductive winding construction minimizes parasitic inductance, making these capacitors suitable for high-frequency switching applications and fast current transient conditions. The low dissipation factor (≤ 0.1% at 1 kHz) and high insulation resistance (≥ 10,000 MΩ) ensure efficient operation with minimal dielectric losses and leakage current. The device is housed in a plastic case with epoxy resin end seals and radial wire leads for through-hole PCB mounting. The UL 94 V-0 flame-retardant plastic case meets safety requirements for power supply and consumer equipment applications. With an operating temperature range of -40°C to +105°C and a 1000-hour life rating at full voltage and 105°C, this capacitor is suitable for demanding industrial environments. As a non-polarized device, it can handle AC voltage applications including line-frequency filtering and AC motor circuits. Overall, the EF3L90CG400H provides a robust, reliable film capacitor solution for high-voltage DC link, power factor correction, inverter, and motor drive applications where long life, self-healing reliability, and high ripple current handling are essential.

A metallized polypropylene film capacitor operates based on the fundamental principle of electrostatic energy storage in a dielectric material. The capacitor consists of two thin plastic films (polypropylene) with a thin metal coating deposited on each film by vacuum metallization — this metal coating serves as the electrode. The two metallized films are wound together (with the metal coatings offset slightly on opposite edges) into a tight roll. The winding is typically done in a non-inductive fashion where the start and end of the winding are configured to minimize inductance. The ends of the wound roll are sprayed with a metal alloy (schooping) to make electrical contact with the exposed edges of the metallized electrodes on each side. Wire leads are then attached to these end-spray connections, and the entire element is encased in a plastic case filled with epoxy resin or other potting compound. When voltage is applied across the terminals, an electric field forms across the polypropylene dielectric between the two metal electrodes, storing energy electrostatically. The polypropylene dielectric has excellent electrical properties: very low dielectric loss (low dissipation factor, typically less than 0.1% at audio frequencies), high insulation resistance, and high dielectric strength (breakdown voltage per unit thickness). Because polypropylene is a non-polar polymer, its properties are relatively stable with frequency and temperature compared to polar dielectrics like polyester. The self-healing property of metallized film construction is a key reliability feature. If a voltage spike or dielectric defect causes a localized breakdown (a short between the two electrodes at a microscopic point), the resulting high current density causes the thin metal electrode to vaporize around the breakdown point. The plasma from the arc pushes the molten metal away, and the dielectric recovers, leaving only a tiny non-conductive area. The capacitor continues to function with only a negligible loss of capacitance. This self-healing makes metallized film capacitors much more failure-resistant than foil-type capacitors, where a single dielectric defect would cause a complete short circuit. However, repeated self-healing events do gradually reduce capacitance over the life of the capacitor. In DC link applications (the most common use for this type and value), the capacitor serves as an energy reservoir on the DC bus of an inverter or converter, maintaining a stable DC voltage and supplying the high-frequency ripple currents drawn by switching power devices. The low ESR, low inductance, and high ripple current capability make metallized PP film capacitors ideal for this role. In PFC circuits, they serve as the output storage capacitor for the boost PFC stage, maintaining a regulated high-voltage DC bus.

The EF3L90CG400H is a 2-terminal, non-polarized, radial-lead through-hole film capacitor.

Package Characteristics:

• Package Style: Cylindrical plastic case, radial wire leads
• Lead Configuration: Radial (leads exit from one end, parallel)
• Lead Pitch (Spacing): Approximately 27.5 mm
• Case Diameter: Approximately 30 mm
• Case Length (Body): Approximately 45 mm
• Lead Diameter: Standard wire gauge for current rating
• Lead Material: Tinned copper-clad steel or copper wire
• Case Material: Flame-retardant plastic (UL 94 V-0)
• Sealing: Epoxy resin end seal
• Mounting: Through-hole PCB mounting
• Polarity: Non-polarized (works in either direction)
• Packaging: Bulk, ammo pack, or tape-and-box for automated insertion

Notes:

• Non-polarized — no polarity marking or orientation requirement
• Suitable for hand soldering and wave soldering
• Observe voltage derating guidelines for long life
• Refer to the official Panasonic EF series datasheet for exact dimensions, ratings, and application guidelines

• DC Link Capacitors (Inverters/Converters): Serves as the DC bus capacitor in three-phase and single-phase inverters, DC-AC converters, and motor drives, providing energy storage and ripple current absorption between the rectifier/PFC stage and the inverter switching stage
• Power Factor Correction (PFC): Used as the output storage capacitor in active PFC boost circuits, maintaining a regulated high-voltage DC bus (typically 380-400VDC) and absorbing the 100/120Hz line-frequency ripple current
• Switching Power Supplies (SMPS): Deployed in high-power switch-mode power supplies for industrial, medical, and telecom applications as bulk storage capacitors on the high-voltage primary side, handling high ripple currents at high switching frequencies
• Motor Drives & VFDs: Used in variable frequency drives and industrial motor controllers as DC link capacitors, absorbing the high-frequency current ripple generated by IGBT or MOSFET switching in the inverter stage
• Lighting Ballasts: Found in high-intensity discharge (HID) lamp ballasts, fluorescent lighting electronic ballasts, and high-power LED drivers for power factor correction, energy storage, and filtering
• Renewable Energy Inverters: Used in string inverters, central inverters, and micro-inverters for solar photovoltaic systems, as well as small wind turbine inverters, providing DC link capacitance and high reliability for outdoor applications
• UPS Systems & Battery Chargers: Deployed in uninterruptible power supplies and industrial battery chargers for DC bus energy storage, inverter output filtering, and input rectifier filtering
• Welding Equipment & Industrial Power: Used in welding power supplies (MIG/TIG/Stick), plasma cutters, and other industrial power electronics requiring high-voltage, high-ripple-current, and long-life capacitor solutions