Re: ESD - time between successive discharges
John: I thought I had lost your original statement about CE not having a bearing on Quality. I would agree also. The statement was made, as I recall, in some article in Compliance Engineering. Not that UL is a quality mark or RU or FCC 15 etc. Quality is highly dependant on how your marketing people perceive it and refers to appearance, dependability, reputation, need fulfillment and a host of things thought to benefit the cutomer - from the manufacturer's view. On the other hand a CE mark is a rating of performance and how many consumers even know about it? I ask every computer salesman I have occasion to meet the meaning of CE and I have yet to find one who knows. After I explain it to him, he agrees that some generic immunity is a good thing. If you look at all the components and larger computer peripherls now bearing a CE mark, it must be cost effective to include it. I suppress consumer equipment that suffers from no immunity with a simple non intrusive method and suggest to the same consumer to be aware and next time look for a product with the CE mark. I yet to encounter a problem with a CE marked product ( modems, video cards, displays, CD players, and even boom boxes) that could never hack it in today's RF environment. CE is a consumer benefit because it guarnatees a minimum level of immunity With all these domestic wireless devices , it makes prudent engineering sense. Designed in is the only way to go. I don't want to do this forever. Ralph Cameron EMC Consulting and Suppression of Consumer Electronics. (after sale) - Original Message - From: John Woodgate j...@jmwa.demon.co.uk To: emc-p...@majordomo.ieee.org Sent: Tuesday, August 07, 2001 4:34 PM Subject: Re: ESD - time between successive discharges 95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com, Ehler, Kyle keh...@lsil.com inimitably wrote: No John, I'm not referring to you. (or anyone else in particular) I dont know you well enough -yet..lol I'm just spaking on how we do the job of ensuring that our products meet the standards. I only pick up typos when they are amusing (like, 'We then repeated the tests for completemess.'), or could create confusion. We take this work very seriously and I agree with you that the CE mark is not a quality mark, Good; my comment was directed to those who might think it is. I agree with most of the rest of your comments. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk This message and its contents are not confidential, privileged or protected by law. Access is only authorised by the intended recipient - this means YOU! The contents may be disclosed to, or used by, anyone and stored or copied in any medium. If you are not the intended recipient, please advise the sender yesterday at the latest. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
Re: ESD - time between successive discharges
95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com, Ehler, Kyle keh...@lsil.com inimitably wrote: No John, I'm not referring to you. (or anyone else in particular) I dont know you well enough -yet..lol I'm just spaking on how we do the job of ensuring that our products meet the standards. I only pick up typos when they are amusing (like, 'We then repeated the tests for completemess.'), or could create confusion. We take this work very seriously and I agree with you that the CE mark is not a quality mark, Good; my comment was directed to those who might think it is. I agree with most of the rest of your comments. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co..uk This message and its contents are not confidential, privileged or protected by law. Access is only authorised by the intended recipient - this means YOU! The contents may be disclosed to, or used by, anyone and stored or copied in any medium. If you are not the intended recipient, please advise the sender yesterday at the latest. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: ESD - time between successive discharges
No John, I'm not referring to you. (or anyone else in particular) I dont know you well enough -yet..lol I'm just spaking on how we do the job of ensuring that our products meet the standards. We take this work very seriously and I agree with you that the CE mark is not a quality mark, but in our case it nearly becomes one when the customer's expectation of our products is to meet (or exceed) the presently applied Directives. We back the CE mark with a detailed test report. In a number of cases, the customer performs follow up testing. On rare occasions, the customer is followup testing to more stringent or severe levels and this is where agressive adherence to the Directives, along with painfully acquired margins, pays off in spades. On very rare occasions a test lab challenges our data, in which case we re-examine and submit or challenge, depending on the issue. I'm a second party and cannot take direct credit for the lab's work, but I can say that I advocate doing the right thing. Even when it creates a great deal of discomfort for our engineers and reasonably increases our costs. As a result, our engineers have at best a rancorous respect for our tiny department. I need to state that our lab is a combined EMC and Safety lab. That it is part of LSI Logic Storage Systems Division, that we are not independent of the company, and that we do no external testing or contracting. Also, what I say here are merely my opinions and are not necessarily those of LSI. standard disclaimer Take Care, Kyle Ehler KCOIQE mailto:kyle.eh...@lsil.com Product Safety Engineer / EMC Specialist LSI Logic Storage Systems Division 3718 N. Rock Road U.S.A. Wichita, Kansas 67226 Ph. 316 636 8657 Fax 316 636 8321 -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Tuesday, August 07, 2001 1:37 AM To: emc-p...@majordomo.ieee.org Subject: Re: ESD - time between successive discharges 95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com, Ehler, Kyle keh...@lsil.com inimitably wrote: I suppose what I am alluring to You aren't alluring to me, sailor!(;-) is debugging for quality, but then, isnt the purpose of compliance testing to 'test to fail' rather than test to pass? No, it isn't, if you mean 'compliance with EU Directives'. To suggest that it is creates an open invitation to militant test-houses to go looking for trouble, and you can be pretty sure that some of them are ingenious enough to find it in every case. [snip] For example, as an OEM (to a few of you out there) and direct mfr. we want to be as thorough as possible because we want to make a quality product and when we put CE on it, we mean it. The CE mark is absolutely NOT to be regarded as a quality mark. Thus spake the European Commission itself. You are welcome to institute whatever product-quality verification programs you wish, but please keep their consideration separate from issues concerning compliance with EU Directives. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk This message and its contents are not confidential, privileged or protected by law. Access is only authorised by the intended recipient - this means YOU! The contents may be disclosed to, or used by, anyone and stored or copied in any medium. If you are not the intended recipient, please advise the sender yesterday at the latest. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
Re: ESD - time between successive discharges
95fbd8b0830ed511b7720002a51363f1319...@exw-ks.ks.lsil.com, Ehler, Kyle keh...@lsil.com inimitably wrote: I suppose what I am alluring to You aren't alluring to me, sailor!(;-) is debugging for quality, but then, isnt the purpose of compliance testing to 'test to fail' rather than test to pass? No, it isn't, if you mean 'compliance with EU Directives'. To suggest that it is creates an open invitation to militant test-houses to go looking for trouble, and you can be pretty sure that some of them are ingenious enough to find it in every case. [snip] For example, as an OEM (to a few of you out there) and direct mfr. we want to be as thorough as possible because we want to make a quality product and when we put CE on it, we mean it. The CE mark is absolutely NOT to be regarded as a quality mark. Thus spake the European Commission itself. You are welcome to institute whatever product-quality verification programs you wish, but please keep their consideration separate from issues concerning compliance with EU Directives. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk This message and its contents are not confidential, privileged or protected by law. Access is only authorised by the intended recipient - this means YOU! The contents may be disclosed to, or used by, anyone and stored or copied in any medium. If you are not the intended recipient, please advise the sender yesterday at the latest. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: ESD - time between successive discharges
I've been following this thread about ESD testing and the PPS debate. I would like to inject my point of view on the subject. So far most of what I have read addresses the need for speed. This is great for the test lab/house; to be able to slam through the process in a quest to get it done quick for the sake of process throughput, but for the purpose of determining if an EUT is immune to a pulse stimuli with respect to possible entry points, I remain skeptical. I suppose what I am alluring to is debugging for quality, but then, isnt the purpose of compliance testing to 'test to fail' rather than test to pass? This may depend on the lab itself. With the PPS issue, I submit that from at least the quality point of view it may depend on the type of product you are testing and the functional test program that the EUT is operating. For example, as an OEM (to a few of you out there) and direct mfr. we want to be as thorough as possible because we want to make a quality product and when we put CE on it, we mean it. We do not want our customer to find a problem with our products during their followup testing (not everyone retests a CE marked product). To ensure quality, we test our cabinet products for a full day or two in the ESD lab (much more if it fails). Many times we have student interns who do this, but sometimes our experienced lab techs do the job. Nevertheless, ESD testing (particularly on our disk arrays) is done very slowly because a rack mount version EUT can be loaded with up to 154 disk drives ranging in capacity from 9 to 180Gb while using a transfer block size ranging from 512 bytes to 256Kb. The result is massive overhead to response. The exercise program for a device such as this (we call it smash/hammer) performs a chained series of write/read/verify operations. The tasking packets may be buffered through a storage attached network (SAN) director and thus the operations can be lengthy and/or latent in the outcome reporting in the error daemon. The only way for our test personnel to determine if a failure has occurred is to monitor the screen of the EUT's host pc to visually verify no errors have occured before proceeding to the next zap. This can take seconds to minutes after a stimuli is applied. If such ESD testing were performed too rapidly, the operator can overlook a failure, and its location. There may be dozens of stimuli injection points to be tested and thus the relative location on the EUT where the failure event occurred can be overlooked. Fortunately, the standard has provision for variety.. Thank-You, Kyle Ehler KCOIQE mailto:kyle.eh...@lsil.com Assistant Design Engineer LSI Logic Corporation 3718 N. Rock Road U.S.A. Wichita, Kansas 67226 Ph. 316 636 8657 Fax 316 636 8321
RE: ESD - time between successive discharges
Our rule is 1 second per discharge, 10 discharges, both polarities, per discharge point. Of course the test personnel also strafe the unit at 20 pulses/second in order to detect any vulnerability that may need to be exploited. -Original Message- From: Cortland Richmond [mailto:72146@compuserve.com] Sent: Saturday, August 04, 2001 8:40 PM To: ieee pstc list Subject: Re: ESD - time between successive discharges This has come up everywhere I've worked. In order to adequately test for vulnerability, logically, one has to apply a discharge during each of the operating conditions an equipment might take. Given the number of different logical states a microprocessor-controlled EUT might use, this could take forever! From the standpoint of doing a conscientious test, it would be desirable to test MORE often than once per second. But because the real-world ESD event is an isolated one, repeated discharges are not a realistic test. Also, many devices incorporate built-in ESD protection using protective parts of limited dissipation, and it is possible testing TOO often will destroy the protection circuit. Once per second turns out to be a compromise, and one which may be followed without being too persnickety. What about a longer interval? Sure -- provided we test all of the logic states that might be latched up by the discharge! Ten discharges per point, plus and minus, at each of the voltage levels prescribed, will probably turn up enough of them to pin down a susceptible device no matter WHAT the interval is. One hour? Well, if you can afford to do thirty hours of test, you can do three points at ONE voltage level. One minute? Still takes a long time. And let's face it; this is mind-numbing work. So one second seems to ME to be just about right. Let the poor tech -- or the poor engineer! -- take a break once in a while! I'll add that there may be failure modes that take longer than one second to show up. You want to do the test in such a way that the tester can note and adjust to this; I once tested something that had a 30 second delay before a failure showed up. This can't be helped, and, in this particular case, one second is far too often. Cortland Richmond --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
Re: ESD - time between successive discharges
This has come up everywhere I've worked. In order to adequately test for vulnerability, logically, one has to apply a discharge during each of the operating conditions an equipment might take. Given the number of different logical states a microprocessor-controlled EUT might use, this could take forever! From the standpoint of doing a conscientious test, it would be desirable to test MORE often than once per second. But because the real-world ESD event is an isolated one, repeated discharges are not a realistic test. Also, many devices incorporate built-in ESD protection using protective parts of limited dissipation, and it is possible testing TOO often will destroy the protection circuit. Once per second turns out to be a compromise, and one which may be followed without being too persnickety. What about a longer interval? Sure -- provided we test all of the logic states that might be latched up by the discharge! Ten discharges per point, plus and minus, at each of the voltage levels prescribed, will probably turn up enough of them to pin down a susceptible device no matter WHAT the interval is. One hour? Well, if you can afford to do thirty hours of test, you can do three points at ONE voltage level. One minute? Still takes a long time. And let's face it; this is mind-numbing work. So one second seems to ME to be just about right. Let the poor tech -- or the poor engineer! -- take a break once in a while! I'll add that there may be failure modes that take longer than one second to show up. You want to do the test in such a way that the tester can note and adjust to this; I once tested something that had a 30 second delay before a failure showed up. This can't be helped, and, in this particular case, one second is far too often. Cortland Richmond --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
Re: ESD - time between successive discharges
Greetings, Let me add something to Joe's position (which I agree with entirely) based upon my experience at a former job. Some products with no ground or not so great grounds will need time (one sec or sometimes more) between discharges to ensure that there is no build up of charge on the system. Not only does charge buildup reduce the effect of same polarity discharges, but just think of the discharge level when a unit with a few kV of charge suddenly gets hit with a -XkV event after the polarity change. The effective net discharge is way over the spec and can often cause perceived failures. For the case of no ground (say a handheld battery powered device), a high impedance drain should be used to remove the charge. Ever pick up a handheld device charged to around 8kV? Best regards Dave Heald Joe Finlayson wrote: Amund, My experience has been that the labs would prefer to perform the ESD tests at a rate of 1 pulse/second (pps) for the sake of efficiency. If the product passes then it was completed in the least amount of time and everyone's happy. If the product fails at 1 pps, then you are allowed to decrease the pulse rate until the product passes. If it still fails at lower rates (say 0.1 pps - one ESD event every 10 seconds), then you probably have problems. I've had products fail at 1 pps and pass at 0.5 pps. It took longer to run the test, but it passed and met the requirements of the standard(s). My interpretation of the requirements is that there is no maximum limit between ESD discharges. Thx, Joe -Original Message- From: am...@westin.org [mailto:am...@westin.org] Sent: Wednesday, August 01, 2001 4:07 PM To: emc-p...@majordomo.ieee.org Subject: ESD - time between successive discharges Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
Re: ESD - time between successive discharges
6bd67ffb937fd411a04f00d0b74fe878026ee...@xrose06.rose.hp.com, HALL,KEN (HP-Roseville,ex1) ken_h...@hp.com inimitably wrote: We believe that the probability of identifying an ESD susceptible product is increased dramatically when subjecting the product to continuous discharges. What you mean is that the result depends on the repetition rate, which is not specified in the standard, so that the test results are not repeatable? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk This message and its contents are not confidential, privileged or protected by law. Access is only authorised by the intended recipient - this means YOU! The contents may be disclosed to, or used by, anyone and stored or copied in any medium. If you are not the intended recipient, please advise the sender yesterday at the latest. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: ESD - time between successive discharges
If the product contains mechanical devices such as disk, floppy, DVD etc and has s/w that has operation cycle times in the neighborhood of 1s or so then the 0.1 to 10 s may have very different results at different points in that timing range. --- Gary McInturff gary.mcintu...@worldwidepackets.com wrote: ESD susceptibility has a couple of components. Simplistically, don't let it happen or try to direct the energy where you want it, and does the event happen at just the right (wrong?) time. Just as a critical gate is changing states for example. Given the relative rate that modern processors are running 800 Mhz - 1 Ghz, I don't know that increasing the discharge rate from a second to 20 or even 50 times a second really increases your ability to capture one of these states. Having said that, I don't really have a quarrel with increasing the rates for investigative purposes, I have done it myself. However, I think you should keep in mind the heating of silicon junctions etc, from the rapid discharge rates. Even non-critical gates can be artificially damaged by rapid pulses. I can't think of a case when an ESD discharge (not lightning etc) naturally occurs at very high rates. I'd be interested in examples if it does occur. Not a bad diagnostic tool but I wouldn't care to see higher rates implemented in standards. Gary (You can't expect much for two cents these days) -Original Message- From: HALL,KEN (HP-Roseville,ex1) [mailto:ken_h...@hp.com] Sent: Thursday, August 02, 2001 7:53 AM To: 'Michael Hopkins'; am...@westin.org; emc-p...@majordomo.ieee.org Cc: AGUILAR,LONNIE (HP-Roseville,ex1); 'Pommerenke, David' Subject: RE: ESD - time between successive discharges Hello all, If I remember correctly the one shot/second was to allow older simulators time to recharge. We believe that the probability of identifying an ESD susceptible product is increased dramatically when subjecting the product to continuous discharges. Ken Hall Lonnie please file. Thanks, Ken -Original Message- From: Michael Hopkins [mailto:mhopk...@thermokeytek.com] Sent: Thursday, August 02, 2001 3:48 AM To: am...@westin.org; emc-p...@majordomo.ieee.org Subject: Re: ESD - time between successive discharges Seems to me the time between discharges is the same as the time between pulses (I believe that was the intent). I don't have the standard in front of me, but I think the max rate was 1/second, which means you could go slower. In most tests I've seen, the several discharges at one point are run at the 1/second rate, but then there could be several seconds or more between the discharges at that point and the discharges at the next point. At least one company actually runs tests at much higher discharge rates and with many more shots/point than IEC recommends (the new draft of ANSI C63.16 goes to 50 shots/per point). Michael Hopkins Thermo KeyTek - Original Message - From: am...@westin.org To: emc-p...@majordomo.ieee.org Sent: Wednesday, August 01, 2001 4:06 PM Subject: ESD - time between successive discharges Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael
RE: ESD - time between successive discharges
ESD susceptibility has a couple of components. Simplistically, don't let it happen or try to direct the energy where you want it, and does the event happen at just the right (wrong?) time. Just as a critical gate is changing states for example. Given the relative rate that modern processors are running 800 Mhz - 1 Ghz, I don't know that increasing the discharge rate from a second to 20 or even 50 times a second really increases your ability to capture one of these states. Having said that, I don't really have a quarrel with increasing the rates for investigative purposes, I have done it myself. However, I think you should keep in mind the heating of silicon junctions etc, from the rapid discharge rates. Even non-critical gates can be artificially damaged by rapid pulses. I can't think of a case when an ESD discharge (not lightning etc) naturally occurs at very high rates. I'd be interested in examples if it does occur. Not a bad diagnostic tool but I wouldn't care to see higher rates implemented in standards. Gary (You can't expect much for two cents these days) -Original Message- From: HALL,KEN (HP-Roseville,ex1) [mailto:ken_h...@hp.com] Sent: Thursday, August 02, 2001 7:53 AM To: 'Michael Hopkins'; am...@westin.org; emc-p...@majordomo.ieee.org Cc: AGUILAR,LONNIE (HP-Roseville,ex1); 'Pommerenke, David' Subject: RE: ESD - time between successive discharges Hello all, If I remember correctly the one shot/second was to allow older simulators time to recharge. We believe that the probability of identifying an ESD susceptible product is increased dramatically when subjecting the product to continuous discharges. Ken Hall Lonnie please file. Thanks, Ken -Original Message- From: Michael Hopkins [mailto:mhopk...@thermokeytek.com] Sent: Thursday, August 02, 2001 3:48 AM To: am...@westin.org; emc-p...@majordomo.ieee.org Subject: Re: ESD - time between successive discharges Seems to me the time between discharges is the same as the time between pulses (I believe that was the intent). I don't have the standard in front of me, but I think the max rate was 1/second, which means you could go slower. In most tests I've seen, the several discharges at one point are run at the 1/second rate, but then there could be several seconds or more between the discharges at that point and the discharges at the next point. At least one company actually runs tests at much higher discharge rates and with many more shots/point than IEC recommends (the new draft of ANSI C63.16 goes to 50 shots/per point). Michael Hopkins Thermo KeyTek - Original Message - From: am...@westin.org To: emc-p...@majordomo.ieee.org Sent: Wednesday, August 01, 2001 4:06 PM Subject: ESD - time between successive discharges Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC
RE: ESD - time between successive discharges
Amund, My experience has been that the labs would prefer to perform the ESD tests at a rate of 1 pulse/second (pps) for the sake of efficiency. If the product passes then it was completed in the least amount of time and everyone's happy. If the product fails at 1 pps, then you are allowed to decrease the pulse rate until the product passes. If it still fails at lower rates (say 0.1 pps - one ESD event every 10 seconds), then you probably have problems. I've had products fail at 1 pps and pass at 0.5 pps. It took longer to run the test, but it passed and met the requirements of the standard(s). My interpretation of the requirements is that there is no maximum limit between ESD discharges. Thx, Joe -Original Message- From: am...@westin.org [mailto:am...@westin.org] Sent: Wednesday, August 01, 2001 4:07 PM To: emc-p...@majordomo.ieee.org Subject: ESD - time between successive discharges Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: ESD - time between successive discharges
Just to give you an idea of how we handled this in 60601-1-2, we said: The time between discharges shall have an initial value of 1 s. Longer time between discharges may be required in order to be able to distinguish between a response caused by a single discharge and a response caused by a number of discharges. That is, each discharge should be evaluated independently. The time between them must be considered based the type of equipment being tested. Hope this helps and is WG13's implementation of this problem. Jim -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Michael Hopkins Sent: Thursday, August 02, 2001 6:48 AM To: am...@westin.org; emc-p...@majordomo.ieee.org Subject: Re: ESD - time between successive discharges Seems to me the time between discharges is the same as the time between pulses (I believe that was the intent). I don't have the standard in front of me, but I think the max rate was 1/second, which means you could go slower. In most tests I've seen, the several discharges at one point are run at the 1/second rate, but then there could be several seconds or more between the discharges at that point and the discharges at the next point. At least one company actually runs tests at much higher discharge rates and with many more shots/point than IEC recommends (the new draft of ANSI C63.16 goes to 50 shots/per point). Michael Hopkins Thermo KeyTek - Original Message - From: am...@westin.org To: emc-p...@majordomo.ieee.org Sent: Wednesday, August 01, 2001 4:06 PM Subject: ESD - time between successive discharges Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
RE: ESD - time between successive discharges
Hello all, If I remember correctly the one shot/second was to allow older simulators time to recharge. We believe that the probability of identifying an ESD susceptible product is increased dramatically when subjecting the product to continuous discharges. Ken Hall Lonnie please file. Thanks, Ken -Original Message- From: Michael Hopkins [mailto:mhopk...@thermokeytek.com] Sent: Thursday, August 02, 2001 3:48 AM To: am...@westin.org; emc-p...@majordomo.ieee.org Subject: Re: ESD - time between successive discharges Seems to me the time between discharges is the same as the time between pulses (I believe that was the intent). I don't have the standard in front of me, but I think the max rate was 1/second, which means you could go slower. In most tests I've seen, the several discharges at one point are run at the 1/second rate, but then there could be several seconds or more between the discharges at that point and the discharges at the next point. At least one company actually runs tests at much higher discharge rates and with many more shots/point than IEC recommends (the new draft of ANSI C63.16 goes to 50 shots/per point). Michael Hopkins Thermo KeyTek - Original Message - From: am...@westin.org To: emc-p...@majordomo.ieee.org Sent: Wednesday, August 01, 2001 4:06 PM Subject: ESD - time between successive discharges Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
Re: ESD - time between successive discharges
Seems to me the time between discharges is the same as the time between pulses (I believe that was the intent). I don't have the standard in front of me, but I think the max rate was 1/second, which means you could go slower. In most tests I've seen, the several discharges at one point are run at the 1/second rate, but then there could be several seconds or more between the discharges at that point and the discharges at the next point. At least one company actually runs tests at much higher discharge rates and with many more shots/point than IEC recommends (the new draft of ANSI C63.16 goes to 50 shots/per point). Michael Hopkins Thermo KeyTek - Original Message - From: am...@westin.org To: emc-p...@majordomo.ieee.org Sent: Wednesday, August 01, 2001 4:06 PM Subject: ESD - time between successive discharges Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall, --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
ESD - time between successive discharges
Dear members, From IEC61000-4-2 and several EN-product standards, they specify the time between successive discharges to be at least 1 second. But what is the maximum time between each pulse ? I can not see that it is stated in any standards. I guess the test labs use 1 pulse pr second. I feel that the pulse rate can have influences on the EUT performance, so 1 second compared to 3-5 seconds might be the difference between PASS and FAIL. Any suggestions ? Best regards Amund Westin Oslo, Norway -- Get your firstname@lastname email for FREE at http://Nameplanet.com/?su --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on Virtual Conference Hall,
