The EE25 5+5 Pin (10-Pin) Vertical Transformer Kit includes a standard EE25 vertical plastic bobbin and two matching PC40 high-permeability manganese-zinc (Mn-Zn) ferrite core halves. Engineered for high-frequency switch-mode power supplies (SMPS), DC-DC converters, flyback transformers, and line filter chokes, this kit delivers high saturation magnetic flux density, low core loss at high frequencies, and excellent thermal stability. Its compact vertical through-hole PCB footprint is ideal for space-constrained power circuit designs.

Specifications

• Core Type / Geometry: EE25 (E-E Configuration, 2 Ferrite Core Halves)
• Bobbin Style: Vertical 5+5 Pin (10-Pin Through-Hole Mount)
• Core Material: PC40 Grade Manganese-Zinc (Mn-Zn) Soft Ferrite
• Initial Permeability (μi): ~2300 ± 25% (at 25°C, 10kHz)
• Saturation Magnetic Flux Density (Bs): ~510mT (at 25°C) / ~390mT (at 100°C)
• Curie Temperature (Tc): ≥ 215°C
• Bobbin Material: Phenolic (Bakelite / UL94 V-0 High-Temperature Flame Retardant)
• Pin Material: Tinned Copper / Brass Solder Pins
• Pin Pitch / Spacing: 5.0mm (Between pins on each row) / 12.5mm (Between rows)
• Operating Frequency Range: 20kHz to 200kHz+ (Optimal for standard PWM/Flyback SMPS controllers)
• Power Handling Capability: Typically 20W to 50W (Dependent on topology, frequency, and wire selection)
• Operating Temperature Range: -25°C to +125°C

Features

• Low High-Frequency Core Losses: Premium PC40 ferrite material minimizes eddy current and hysteresis losses at switching frequencies up to 200kHz+.
• High Saturation Resistance: Maintains stable magnetic performance under peak primary currents without premature core saturation.
• Space-Saving Vertical Orientation: Minimizes PCB footprint area, leaving more board surface for surrounding filters and switching MOSFETs.
• Flame-Retardant UL94 V-0 Bobbin: Heat-resistant phenolic construction withstands direct wave soldering and high internal winding temperatures.
• Versatile 10-Pin Layout: 5+5 pin arrangement provides ample isolated termination points for primary windings, auxiliary bias windings, and multi-tap secondary rails.

Common Applications

• Switch-Mode Power Supplies (SMPS): Flyback and forward transformer stages for AC-DC adapters (12V, 24V, 5V power bricks).
• DC-DC Boost / Buck-Boost Converters: High-frequency isolated power conversion in renewable and battery-powered systems.
• Inverter Auxiliary Supplies: Gate-drive power transformers and low-voltage auxiliary bias supplies for solar and motor inverters.
• LED Driver Power Supplies: Constant-current/constant-voltage mains-powered LED lighting supplies.
• EMI & Common-Mode Filters: Custom inductors and coupled chokes for input power filtering.

Usage Tips

• Air Gap Considerations: For flyback converter topologies, introduce a calibrated air gap (using ground center legs or Kapton/Mylar spacer tape) to prevent core saturation under DC bias current.
• Winding Insulation: Use high-dielectric yellow Mylar/polyester margin tape between primary, auxiliary, and secondary windings to meet 3kV+ isolation standards.
• Securing Ferrite Halves: After winding, clamp the two core halves securely using high-temperature transformer tape, metal core clips, or electronic-grade epoxy adhesive.
• Soldering Safety: Solder pins quickly at 350°C (maximum 3 seconds per pin) to prevent terminal loosening or bobbin warping.

Datasheet