As devices get smaller and smaller, switching power supplies also need to shrink in size to fit into the space available. This translates into higher switching frequency and Coilcraft have introduced a new range of miniature coils for switching regulators with a working range of 2 to 5 MHz at high values of current.

Smaller coils store less magnetic energy per clock so operating frequency and current needs to be boosted to allow the use of smaller values of inductance. Coilcraft's new XEL50xx series measure just 5.28 x 5.48mm with 3.2 mm maximum height. Currently available are the XEL5020 and XEL5030 series. A third version (XEL5050) is expected in the second quarter of 2018.

The XEL5020 is available in six inductance values from 0.1 to 1 μH with current ratings from 12 to 39 A with an ohmic resistance of 2 to 12 mΩ and height of 2.1 to 2.2 mm. The type XEL5020-381ME for example is 0.38 μH at 4.8 mΩ with a saturation current of 22 A and a series resonance of 89 MHz. Operation at 12 A will produce a temperature rise of 20 °C (15 A = 40 °C). The XEL5030 series offers 10 values ​​from 0.13 to 4.7 μH and maximum current up to 44 A.

According to Coilcraft, all coils comply with the AEC-Q200 Grade 1 (40 to +125 °C ambient temperature) standard with a maximum component temperature of +165 ° C. They are therefore also suitable for the automotive sector and harsh environmental conditions. In addition their composite construction ensures minimal audible buzzing. Compared to the 20 series, the 30 series is about 3 mm high and the 50 series corresponding to 5 mm. All three series have the same footprint and are therefore interchangeable on the board.