Max Current for Inductors

  1. I would like to use the MPL-AY3020-4R7 4.7uH inductor with the MP2182 which is a 2A buck converter. That inductor is rated for 2A and has a 3.1A saturation current. Should I be concerned about a possible short circuit where the current will exceed 3.5A?

The data sheet for the MPL-AY3020-4R7 shows a fairly flat curve of inductance vs current. At 4A the inductance is still above 2.8uH, so it will withstand the current. However, the data sheet also shows an excessive 100ºC rise in temperature at 2.8A. At higher currents, even when short circuit protection is tripped, the reliability of the inductor could be compromised. If the short circuit condition must be met, a higher current rating is needed along with a lower temperature rise. The MPL-AO4020-4R7 has a saturation current of 4.2A and a temperature rise at 3.5A of 40ºC, making it a better match for the 3.5A requirement.