Inductor saturation due to high dv/dt

  • #1
636
2
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?
 

Answers and Replies

  • #2
766
79
You have confirmed that it is the inductor that is getting hot?
 
  • #3
sophiecentaur
Science Advisor
Gold Member
2020 Award
26,148
5,365
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
636
2
The Core type is Ferrite.
 
  • #6
1,418
383
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
636
2
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
1,418
383
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
 

Related Threads on Inductor saturation due to high dv/dt

Replies
28
Views
4K
Replies
3
Views
5K
Replies
8
Views
7K
Replies
76
Views
9K
Replies
8
Views
4K
Replies
3
Views
1K
  • Last Post
Replies
5
Views
2K
Replies
5
Views
3K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
10
Views
20K
Top