Planar Magnetics

Advanced by Quantic ECI in the mid 1980's, "Planar Magnetics" is a component topology typically characterized by low profile core structures utilizing laminated or copper lead-frame windings in place of conventional magnet wire.

Applications for planar magnetics technology are in switching power supply circuits of various topologies including Flyback, Forward, Push-Pull, Half or Full Bridge, Resonant, etc.  Typical input voltages range from DC-DC to Off-Line, switching frequencies from 20kHz to 2MHz, output power up to 20kW, and output currents up to 200A. 

Using ECI’s planar magnetics approach allows the various windings to be interleaved, thus minimizing parasitic leakage inductance. Terminations can be located & arranged to suit specific applications, including meeting creepage & clearance requirements.  Devices can be terminated using a variety of methods including thru-hole, SMT (nail-head pins, pads, or gull-wing) or edge mount.  Insulation materials range from high Tg FR-4 to Polyimide or ceramic.  

For a custom designed ECI planar transformer, complete the "custom planar design worksheet", and forward to ECI.

Advantages of planar transformers include:

  • Inherent low-profile structure
  • High power density
  • Low leakage inductance
  • Minimized skin & proximity effect losses
  • Highly controlled transformer parasitics
  • Minimizes corona and partial discharge (multilayer PCB approach)
  • Excellent performance repeatability (high cpk)
  • Low radiated EMI
  • High surface area to volume ratio maximizes heat dissipation
  • Solid construction (multilayer PCB approach) minimizes thermal resistance
  • Accommodates many windings
  • Flexible pin-out patterns