Power supplies are one of those exceptions where derating is rarely useful. In general, a power supply should be sized to run at about 80% to 90% of capacity at peak load. Absent special circumstances, there is little to no benefit in running at a small fraction of supply capability. You mentioned power ICs in the subject line and power supplies in your text. These are not quite the same thing. Note that in the case of linear regulator ICs, derating works as well as for any other linear IC, and using them at a fraction of capacity is ordinary practice, often to simplify thermal management. Orin Laney -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Sandhya I. M. Sent: Thursday, July 21, 2011 3:43 AM To: SI-LIST Subject: [SI-LIST] Derating Value of Power ICs Hi Experts, I am doing power analysis of our design. Can anyone help me to calculate the de-rating value of power supplies? I did a google search and not able to conclude how could I get those values. My data sheet or any other documents of the IC does not provide derating value directly or in any graph. Pls help. Regards, SIM ***** Confidentiality Statement/Disclaimer ***** This message and any attachments is intended for the sole use of the intended recipient. It may contain confidential information. Any unauthorized use, dissemination or modification is strictly prohibited. If you are not the intended recipient, please notify the sender immediately then delete it from all your systems, and do not copy, use or print. Internet communications are not secure and it is the responsibility of the recipient to make sure that it is virus/malicious code exempt. The company/sender cannot be responsible for any unauthorized alterations or modifications made to the contents. If you require any form of confirmation of the contents, please contact the company/sender. The company/sender is not liable for any errors or omissions in the content of this message. ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net 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 technical documents are available at: http://www.si-list.net 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