Which is why I run a separate wire. -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Douglas Smith Sent: Wednesday, September 24, 2014 12:00 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: ESD failure - need advise I do not find simple general rules like this to be useful. On average, systems with circuit and chassis ground strongly interconnected do best for ESD immunity. I have confirmed this over hundreds of systems and thousands ofmeasurements. There is always a possibility of an exception. That wire carrying ESD to chassis can induce tens to hundreds of Volts/inch in nearby conductors! Doug On 9/23/14 4:16 PM, Orin Laney wrote: One useful strategy is to provided a trace, metal rail, etc. to intercept thezap and conduct it directly to the chassis without sharing with circuit grounds. In other words, it's a lightning rod. Somewhere else in the system the chassis and circuit are presumably tied together, but not as part of thispath. Shunting the zap works better than trying to prevent it with insulation and distance. Orin -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx[1] [mailto:si-list-bounce@xxxxxxxxxxxxx[2]] On Behalf Of Ramesh N Sent: Tuesday, September 23, 2014 3:48 PM To: si-list@xxxxxxxxxxxxx[3] Subject: [SI-LIST] ESD failure - need advise Hello Experts, Greetings!!! we are having ESD fail (in regulatory testing) in one of our design. It's simple wireless DAQ system with 2 boards [controller PCB + LED/Sensor PCB]. FPC cable (5") is used as interconnect.Package is abs plastics. Light-pipe is used for the for led indication. When +8kV is appliedthrough air discharging, inadvertent LED trigger occurs . Randomly, system is also hanging when multiple zapping applied (especially for 8kV voltage level). I have tried to limit airgaps, added filter caps, etc but issue is not entirely solved. Is there any ESD simulation/analysis tool available for addressing this failure analysis? Any help/debug tips related to this would be very helpful. Thanks and regards, Ramesh ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx[4] with 'unsubscribe'in the Subject field or to administer your membership from a webpage, go to: //www.freelists.org/webpage/si-list[5] For help: si-list-request@xxxxxxxxxxxxx[6] with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list[7] List archivesare viewable at: //www.freelists.org/archives/si-list[8] Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu[9] ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx[10] with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list[11] For help: si-list-request@xxxxxxxxxxxxx[12] with 'help' in the Subject field List forumis accessible at: http://tech.groups.yahoo.com/group/si-list[13] List archives are viewable at: //www.freelists.org/archives/si-list[14] Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu[15] --- Links --- 1 mailto:si-list-bounce@xxxxxxxxxxxxx 2 mailto:si-list-bounce@xxxxxxxxxxxxx 3 mailto:si-list@xxxxxxxxxxxxx 4 mailto:si-list-request@xxxxxxxxxxxxx 5 //www.freelists.org/webpage/si-list 6 mailto:si-list-request@xxxxxxxxxxxxx 7 http://tech.groups.yahoo.com/group/si-list 8 //www.freelists.org/archives/si-list 9 http://www.qsl.net/wb6tpu 10 mailto:si-list-request@xxxxxxxxxxxxx 11 //www.freelists.org/webpage/si-list 12 mailto:si-list-request@xxxxxxxxxxxxx 13 http://tech.groups.yahoo.com/group/si-list 14 //www.freelists.org/archives/si-list 15 http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu