What is the difference between Current Rating and Saturation Current?
This is in reference to Inductors
Current Rating is the maximum current the gauge of wire used in the inductor can handle at the rated temperature range.
Saturation Current is the point where the magnetic field no longer increases proportionally with an increase in current. The core has become ‘saturated’. Operating at or above the Saturation Current, temperature derating should be considered.
Thank you…
Consider a inductor with Rated current 10A and Saturation current 15A.
As per your explanation, this inductor allow maximum current only upto 10A.
When the magnetic field is maximum, the current at same point is called Saturation current.
In this case, how does the inductor carry 15A Saturation current when the current rating is lesser (10A). Wire Gauge may burnout. Right ?
The current rating can be applied at a constant rate without thermal damage. This is a safe rule of thumb but a current above the ‘current rating’ can be achieved when considering carefully the time and temperature rise. The saturation current is where the Inductance drops to a specified level in the datasheet.
We can look at part number 541-1086-1-ND as an example. 680nH 10A current rating with 15A saturation current.
Note (1) At the rated 10A we can see the L inductance will be .680uH at 40°C. As the current increases we can see from the graph the L inductance decreases. Note (2) in their specs at saturation current the inductance has decreased by 20% of the nominal rating of .680uH.
