Inductor saturation due to high dv/dt

In summary: Core losses due to eddy (circulating) currents. This is the reasoning for laminated steel to be used in the cores for transformers - it forces the currents into the individual laminations - smaller loops... smaller currents... smaller losses.
  • #1
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I have a buck regulator running hot. I reduced the switching frequency and the temperature is almost normal.
The current rating of the inductor is high(2A) compared to current consumption on the board (300mA).
Why does reducing the switching frequency solve the heat problem?
Does the inductor core get hot due to high dv/dt at the switching node?
 
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  • #2
You have confirmed that it is the inductor that is getting hot?
 
  • #3
Magnetic materials can have high losses when operating above their design frequency. What is the core material you are using? You could find out its characteristics from the manufacturers.
 
  • #4
The Core type is Ferrite.
 
  • #5
the_emi_guy said:
You have confirmed that it is the inductor that is getting hot?
Yes.
 
  • #6
It is not hi dV/Dt - but high dI/dt - or higher frequency causing higher losses. When you magnetize a core ( both a magnetic and conductive material) the expansion and contraction of the flux lines (changing flux) within the core - cause currents. The higher the frequency ( as well as harmonics) the more currents are induced and collapsed in the core material itself - yielding higher losses = heat.
 
  • #7
Windadct said:
It is not hi dV/Dt - but high dI/dt - or higher frequency causing higher losses. When you magnetize a core ( both a magnetic and conductive material) the expansion and contraction of the flux lines (changing flux) within the core - cause currents. The higher the frequency ( as well as harmonics) the more currents are induced and collapsed in the core material itself - yielding higher losses = heat.

Windact, can you tell me the techincal term for this loss mechanism.
 
  • #8
Ummm.. I think just referred to as core losses due to eddy (circulating) currents. This is the reasoning for laminated steel to be used in the cores for transformers - it forces the currents into the individual laminations - smaller loops... smaller currents... smaller losses

Scroll down on this page... http://www.electronics-tutorials.ws/transformer/transformer-construction.html
 

1. What is inductor saturation due to high dv/dt?

Inductor saturation due to high dv/dt is a phenomenon that occurs when the voltage across an inductor changes rapidly, causing the inductor to reach its maximum magnetic flux density and become temporarily unable to store any more energy.

2. What causes inductor saturation due to high dv/dt?

Inductor saturation due to high dv/dt is caused by a rapid change in voltage across the inductor. This can be due to factors such as sudden changes in current, switching of circuits, or the use of high frequency signals.

3. How does inductor saturation due to high dv/dt affect circuit performance?

When an inductor saturates due to high dv/dt, it can cause the inductor to behave like a resistor, resulting in a significant increase in the overall impedance of the circuit. This can lead to issues such as voltage spikes, distortion, and loss of efficiency.

4. How can inductor saturation due to high dv/dt be prevented?

Inductor saturation due to high dv/dt can be prevented by using inductors with a higher saturation current rating, reducing the rate of change in voltage across the inductor, or implementing other circuit design techniques such as adding snubber circuits or using ferrite beads.

5. What are the potential consequences of inductor saturation due to high dv/dt?

The consequences of inductor saturation due to high dv/dt can include damage to the inductor, failure of the circuit or system, and inaccurate or unreliable performance. It can also result in increased heat dissipation and reduced lifespan of components.

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