OPENCORES.ORG

-----Original Message-----

Try

http://www.semtech.com/pdf/rclamp0504m.pdf

or similar products.

Marc Reinig
System Solutions

> -----Original Message-----
> From: usb-bounces@o...
> [mailto:usb-bounces@o...]On Behalf Of Paal Tamas
> Sent: Tuesday, February 10, 2004 9:14 AM
> To: Discussion list about free, open source USB IP core
> Subject: RE: [usb] USB HUB IPCore
>
>
> Marc,
>
> The circuit works in the 50v...800v region. In the 50v...150v region it
> works fine without any galvanic isolation, but going higher with the
> system bus voltage, the USB communication fails.
> The USB functionality is integrated into the microcontroller,
> that's why I
> cannot put the isolation between the USB controller and the micro.
>
> The main problem is the ground loop, that can develope, if I directly
> connect the USB into the PC. (The PC ground and the power ground of
> the circuit is (at least) capacitively connected, so after the USB
> connection is made, another ground connection developes, making a
> big ground loop.)
>
> Tom
>
> Marc Reinig  írta:
>
> > What are the specs of your high voltage problem? 50V, 500V,
> 5000V, ...
> >
> > Why not isolate the USB chip from the high voltage instead of trying to
> > isolate D+/D-?
> >
> > Marc Reinig
> > System Solutions
> >
> > > -----Original Message-----
> > > From: usb-bounces@o...
> > > [mailto:usb-bounces@o...]On Behalf Of Paal Tamas
> > > Sent: Monday, February 09, 2004 5:15 AM
> > > To: usb@o...
> > > Subject: [usb] USB HUB IPCore
> > >
> > >
> > > Hi,
> > >
> > > Is there anyone who ever thought about making a Full Speed USB
> HUB
> > > IP core?
> > >
> > > Why I need that?:
> > > I am developing a USB interface for a high voltage device, and was
> > > thinking about a way, to galvanically isolate the USB port (e.g. the
> PC)
> > > from the rest of the circuit.
> > > I know, that there are this kind of gadgets on the market, but they
> are
> > > a bit expensive for my application (200..300USD).
> > > I thing the best way to do this, is to implement the USB device into
> an
> > > FPGA, and isolate the signals from the FPGA to the SIE. I
> will do this
> in
> > > the future, but now I have to keep my USB chip, and put a (cheap)
> > > isolation outside the circuit.  This isolator could be a HUB
> implemented
> > > in an FPGA with isolated lines to the SIE(s).
> > >
> > > Please notify me, if you have a USB HUB IP core implementation in
> mind.
> > >
> > > Tom
> > >
> > >
> > >
> > > _______________________________________________
> > > http://www.opencores.org/mailman/listinfo/usb
> >
> >
> > _______________________________________________
> > http://www.opencores.org/mailman/listinfo/usb
> >
> >
> >
>
>
>
>
>
> _______________________________________________
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