Inductors

Inductors and transformers consist of special ferrite or laminated cores or amorphous/nanocrystalline materials onto which one or several windings of metal wire have been applied. The greater the permeability and the number of windings, the higher the inductance. Alternatively, they may be manufactured in multilayer technology. In this case, conducting patterns are printed onto the individual layers of multilayer ferrite ceramics, which are then stacked to produce a coil.

The simplest inductor designs are chokes with only a single winding. They are used to filter RF interference, especially in communications and power engineering. The designs of these chokes are very diverse and depend on the required current capability and inductance. Thus, miniaturized SMT components are used in communications engineering, whereas large components with laminated cores are widely used in power engineering. Storage chokes are key components for state-of-the-art switch mode power supplies. They store magnetic energy and simultaneously smooth the output currents and voltages.

Transformers have at least two windings on a ferrite, laminated or amorphous/nanocrystalline core. Like chokes, they are also used mainly in communications and power engineering. However, their job is impedance matching and electrical isolation as well as current measurement and power transmission. Transformers also have a very wide range of case types and sizes, as required by their various applications.

Special EMC filters, current-compensated or common-mode chokes are used to assure the electromagnetic compatibility of data and power lines. Their main applications are in CAN bus systems and interfaces in consumer electronics as well as all types of power supplies.

Applications in power engineering:

• Frequency converters
• Lamp ballasts
• Solar inverters
• Power supplies, switch mode
• Power supplies, uninterruptable
• Automotive electronics systems
• Converters for wind power plants
• Current measurement devices

Applications in communications engineering:

• Baluns
• Electrical isolation in DSL systems
• RF filters
• Interface interference suppression in communications electronics

SMT inductors are used to filter signal and data lines. They eliminate RF interference.

Transformers for power supplies (left) and DSL applications (right). Transformers ensure electrical isolation, impedance matching and power transmission.

Combining ceramic materials and innovative inner electrode design.