[SI-LIST] Re: LED with series bead
- From: steve weir <weirsi@xxxxxxxxxx>
- To: zhuyongfa@xxxxxxxxxx
- Date: Wed, 07 Nov 2007 19:46:10 -0800
Beads sometimes get applied to front panel LEDs, switches and such in
the belief that this will limit EMI radiation and/or ESD
susceptibility. You can decide for yourself if you think, there is a
lot that a ferrite bead is going to do that a 100-300 Ohm current limit
resistor doesn't already do.
Steve.
z46147 wrote:
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> Hi all,
>
> I also want to know root cause of this application.
>
> Any thought on it would be appreciated.
>
> Best regards.
>
> Zhuyongfa
> HUAWEI TECHNOLOGIES CO.,LTD.
>
>
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> ----- Original Message -----
> From: Vijay Anand
> To: si-list@xxxxxxxxxxxxx
> Sent: Tuesday, November 06, 2007 6:30 PM
> Subject: [SI-LIST] LED with series bead
>
>
> Dear All,
> In our design we connect a bead in series with LED while driving from an
> I/O pin. I dont know why this bead is connected ( still series resistor is
> there for current limiting). Is there is any relation with EMI? Kindly do the
> needful.
> With Regards,
> Vijay Anand. G
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