Measuring Accurate Inductance of an SMD Inductor or Coil

Sometimes you may end up having to measure the inductance of inductors which do not have part marking to confirm their identification, such as SMD inductors or coils. To measure inductive components correctly, you need to refer to their datasheet for the following testing conditions:

Testing frequency
Normally the datasheet will show a specific frequency as the measuring condition since most of a coil’s inductance and its efficiency are frequency dependent.

Testing Current/Signal Level
Sometimes a datasheet does not show the testing current for your inductance specification; however, since most inductors are designated for a rated current, you can assume rated and testing current are the same and configure the testing current as the rated current.

Below, we will use Murata’s LQW15AN6N8G00D as an example.

The testing frequency is 100MHz.

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The testing current and signal level should be set as 700mA and 0dB.

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If the test current does not reach the rated current, the measuring result would be lower than the specification, such as if the LQW15AN6N8G00D is tested in 1~2mA, the result may be as low as 5.4nH.

For more information, check out more inductor posts: