Jason, two questions: 1.What would happen if your GND is not connected to the protective earth? 2. Where can flow a huge negative potential from the input line which is susceptible to the ESD? see the schematic in fig.2 http://www.datasheetdir.com/EMIF02-USB02F2+download Vasile On Sat, Nov 29, 2014 at 3:32 AM, Jason White < whitewaterssoftwareinfo@gmail.com> wrote: > See Below as well as the attached schematic snippit. > > > On Fri, Nov 28, 2014 at 12:41 PM, Sean Breheny wrote: > > One more item - the series inductor really needs to be a type which wil= l > be > > lossy at the frequencies encountered in ESD (1MHz to 1GHz), so it will > > almost certainly be a ferrite bead with one or a small number of turns. > If > > you tried to use an air core inductor, it might resonate with the > capacitor > > and fail to dissipate the energy until the TVS clamped. > > I chose the CIC10P471NC ferrite filter (see[1]), its impedance is > specified to be 470 ohms at 100MHz. Is this the type of device you > were recommending? > > [1] > http://www.digikey.com/product-detail/en/CIC10P471NC/1276-6358-1-ND/39737= 42 > > > On Fri, Nov 28, 2014 at 4:25 PM, Brent Brown > wrote: > > No resistor to ground may leave the input susceptible to noise, but ho= w > important that is to you will depend on the environment/length or wires e= tc. > > I didn't think of that, I will certainly add it. > > > Thanks Sean and Brent! > -Jason White > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .