Switching inductors

Technical description

Linear storage chokes are widely used in switching power supply circuits which operate in forward mode. Their task is to level the output current by storing the energy during the conduction time of the power semiconductors and by releasing it during the off time. The filter inductors are normally used in output circuits of the switching power supplies in order to reduce the voltage and current ripple. In both cases the inductors operate with high DC currents.

UTK switching inductors are designed for high storage energy values and low losses at high switching frequencies. In order to minimize the physical dimensions they are wound on iron powder toroidal cores and operate with flux density close to saturation. The windings on a single layer provide low interwinding capacitance and good noise immunity up to high frequencies.

A wide range of standard products is available for the most common applications. In order to satisfy specific requirements UTK Component can develop special products according to the customers' needs. Storage and filter chokes for single-chip DC/DC converters of the National Semiconductor SIMPLE SWITCHER‚ family (LM259X e LM267X) are also available.

UTK Component switching inductors have the following characteristics.

  • Compact size, wound on iron powder toroidal cores, for vertical and horizontal PCB mounting.
  • Nominal currents from 0.25A to 10 A.
  • Inductance values from 15μH to 10000mH
  • High working frequency, up to 100KHz
  • Low losses

UTK Component controls closely the production during the process and at the end of it, granting the quality and reliability of the product. The carried out tests include:

  • Visual inspection
  • Value of the reference parameters

Reference parameters

Inductance Ln
Nominal value of the inductance without DC current. Measured with LCR meter (Ambient temp 25°C, frequency 10KHz, drive UAC,rms=0.5Vac). Tolerance +/- 25%.

Nominal current In
Nominal DC offset current.

Winding resistance R
Winding resistance measured with LCR meter.

Frequency Fmax
Maximum working frequency.