Re: shielded inductor -> low frequency?

Michael wrote:
Greetings gents of the SED variety - I have a couple quick questions
for you all:

I am working on a DC/DC switcher that will use the Linear LT1930A. It
switches at 2.2MHz. I need to find a ~8-10uH inductor that can handle
about .5-1A for this. I identified the Sumida CR43 series as a good
candidate. For example, there is a 8.2uH (at 7.96MHz) CR43 series with
166.2mohms DCR speced at 0.84A. It also has a very small 4.3x4.8mm
footprint. It would be perfect, except that it isn't shielded. I would
really prefer it to be shielded. I started looking at other Sumida
inductors, and it seems that all the shielded ones are speced in the
low KHz region. Am I missing something here?

Also, what is the relationship between inductance and frequency? I
googled around about that for a bit but couldn't find anything.

Thanks,

-Michael



Electrostatic (conductive) Shielding does not effect the magnetic lines of flux you need high u material for that. and high u magnetic shielding material only works at low < 100Kc frequency.


so placing a metal can around a coil is only partially effective in reducing radiated emissions.

Marc

marc


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Relevant Pages

  • Re: shielded inductor -> low frequency?
    ... I am working on a DC/DC switcher that will use the Linear LT1930A. ... Electrostatic Shielding does not effect the magnetic lines of flux you need high u material for that. ... Closed path is what inductor company marketeers call "shielded". ... ARE YO MENAING THAT WINFDINGING THE COIL ON A TORRUS, CNTAINS THE STRAY MAGNETCI FEILD FLINES? ...
    (sci.electronics.design)
  • Re: shielded inductor -> low frequency?
    ... I am working on a DC/DC switcher that will use the Linear LT1930A. ... Electrostatic Shielding does not effect the magnetic lines of flux you need high u material for that. ... Closed path is what inductor company marketeers call "shielded". ... ARE YO MENAING THAT WINFDINGING THE COIL ON A TORRUS, CNTAINS THE STRAY MAGNETCI FEILD FLINES? ...
    (sci.electronics.design)
  • Re: shielded inductor -> low frequency?
    ... I am working on a DC/DC switcher that will use the Linear LT1930A. ... Electrostatic Shielding does not effect the magnetic lines of flux you need high u material for that. ... Closed path is what inductor company marketeers call "shielded". ... For example, a ferrite toroid would be quite good in that respect, that's what I usually use. ...
    (sci.electronics.design)
  • Re: shielded inductor -> low frequency?
    ... I am working on a DC/DC switcher that will use the Linear LT1930A. ... Electrostatic Shielding does not effect the magnetic lines of flux you need high u material for that. ... I believe what Michael meant is a closed versus open magnetic path. ... Closed path is what inductor company marketeers call "shielded". ...
    (sci.electronics.design)
  • Re: shielded inductor -> low frequency?
    ... I am working on a DC/DC switcher that will use the Linear LT1930A. ... I need to find a ~8-10uH inductor that can handle ... Electrostatic Shielding does not effect the magnetic lines of flux you need high u material for that. ... People are always focusing on the skin depth argument (how the surface field penetrates the bulk) and not the shorted-turn argument. ...
    (sci.electronics.design)
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