Dear John,
But many times I realised that connecting the shield conductor of the
USB cable to the digital ground of the circuitry in the PCB improved the
ESD / EFT immunity. Leaving the USB cable shield conductor open (either at
device end or at computer end) worsens the situation. In the device
introducing a ferrite bead between the digital ground of the circuitry and
the shield conductor of the USB cable also worsened the ESD situation.
K. BALA
Manager - Hardware
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|John Woodgate <[email protected]>
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|[email protected]
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|01/06/2010 02:02 PM
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|Re: ESD Test Failure of Stainless USB Mouse
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In message <[email protected]>, dated Tue, 5 Jan 2010, Doug
Smith <[email protected]> writes:
>the cable shield has to be closely referenced to the signal ground of
>the receiver to prevent common mode overload problems.
That could be incorrectly interpreted as a recommendation to connect the
shield to the PC board. I'm sure you didn't mean that.
--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk. and www.isce.org.uk
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
I should be disillusioned, but it's not worth the effort.
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This message is from the IEEE Product Safety Engineering Society emc-pstc
discussion list. To post a message to the list, send your e-mail to
<[email protected]>
All emc-pstc postings are archived and searchable on the web at:
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