Power inductors designers are having to accommodate higher rms and ripple current values at frequencies as high as 500 kHz.. Technical trends in power inductors include higher power levels which translate to higher current carrying capability, higher frequency of operation, and higher ripple currents. Packaging trends include smaller size and higher power density, and the use of higher temperature materials as a result of higher operating temperatures.
Technical trends with transformers include higher power levels and higher frequency of operation. Design state of the art now would be a 10 kW transformer operating at 250 kHz. At lower power levels frequency can be up to 1 MHz.
As a consequence of the higher frequency, the parasitic properties (leakage inductance and capacitance) are becoming more important, and are often part of the customer’s specification. The use of resonant circuit topologies, and circuits which combine inductive filtering with voltage transformation in a single device are also driving a new set of technical requirements for transformers.