Hi Pat, I've been performing some PI / Thermal co-simulations using HyperLynx on one of our high current designs. But, from my experience so far with the simulation results, it is not that straight forward to accurately assess the thresholds. I believe a lot more insight is needed to collaborate the simulation data accurately. I'm still waiting on thermal imaging data from lab to determine how close / far we are from simulation. Regards, Arjun Bingipur Senior PCB Design Engineer Electronics & Instrumentation Yazaki Europe Ltd - Hemel Hempstead United Kingdom Tel: +44(0) 1442 839543 Email: arjun.bingipur@xxxxxxxxxxxxxxxxx "Carrier, Patrick" <Patrick_Carrier@xxxxxxxxxx> Sent by: si-list-bounce@xxxxxxxxxxxxx 12/04/2012 14:58 Please respond to Patrick_Carrier@xxxxxxxxxx To "balaseven@xxxxxxxxx" <balaseven@xxxxxxxxx>, "si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx> cc Subject [SI-LIST] Re: DC power Analysis/Current Density Hi Bala-- The relationship between current density and temperature rise is a complicated one that has a number of "it depends" types of factors, most notably how an area of high current density is connected to the rest of the plane. That will be one of the determining factors in how the heat will dissipate from that area. It is best to do a PI/Thermal co-simulation simulation to assess this accurately. Even IPC-2152, the new current/thermal specification, advocates simulation as a means to solving this problem. The following webinar will probably be of interest to you: http://www.mentor.com/products/pcb-system-design/multimedia/don-t-let-integrated-circuit-power-demands-heat-up-your-board --Pat -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of bala Sent: Thursday, April 12, 2012 7:29 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] DC power Analysis/Current Density Hi Experts, I have a question on 'DC power analysis'. Hope the maximum allowed IR drop/V-drop value can be concluded from the line/load regulation. Is there any general formula to find out a maximum allowed 'current density' for a particular power plane? For example, if I want to simulate 3.3V, 0.8A plane@maximum of 70 degree Celsius, how shall we find out the maximum allowed current density for this case? Regards bala ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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