From: chrisjc31415@yahoo.co.uk (Chris Cowdery) Newsgroups: comp.arch.fpga Subject: Using a battery instead of Config device Date: 6 Mar 2002 09:28:14 -0800 Organization: http://groups.google.com/ Lines: 10 Message-ID: <685ae314.0203060928.16ef5215@posting.google.com> NNTP-Posting-Host: 213.2.27.179 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1015435696 22947 127.0.0.1 (6 Mar 2002 17:28:16 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 6 Mar 2002 17:28:16 GMT Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.stanford.edu!postnews1.google.com!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:14973 I am considering using a lithium battery on a board instead of a config device to enable my Altera FLEX10KA to retain its configuration. Has anyone any idea of the absolute min quiescent current I can expect a 10KA to draw? Thanks, Chris. ###### Message-ID: <3C86D98F.1305708A@earthlink.net> From: Peter Alfke X-Mailer: Mozilla 4.61 (Macintosh; I; PPC) X-Accept-Language: en,pdf MIME-Version: 1.0 Newsgroups: comp.arch.fpga Subject: Re: Using a battery instead of Config device References: <685ae314.0203060928.16ef5215@posting.google.com> Content-Type: text/plain; charset=us-ascii; x-mac-type="54455854"; x-mac-creator="4D4F5353" Content-Transfer-Encoding: 7bit Lines: 33 Date: Thu, 07 Mar 2002 03:08:19 GMT NNTP-Posting-Host: 209.179.194.132 X-Complaints-To: abuse@earthlink.net X-Trace: newsread2.prod.itd.earthlink.net 1015470499 209.179.194.132 (Wed, 06 Mar 2002 19:08:19 PST) NNTP-Posting-Date: Wed, 06 Mar 2002 19:08:19 PST Organization: EarthLink Inc. -- http://www.EarthLink.net X-Received-Date: Wed, 06 Mar 2002 19:08:10 PST (newsmaster1.prod.itd.earthlink.net) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!newsfeed.icl.net!newsfeed.cwix.com!feed2.news.rcn.net!rcn!newsfeed1.earthlink.net!newsfeed.earthlink.net!newsmaster1.prod.itd.earthlink.net!newsread2.prod.itd.earthlink.net.POSTED!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:15012 I can obviously not speak for Altera, but here are some general observations: If the manufacturer made sure that all dc-consuming utilities are turned off as soon as the normal Vcc disappears, and if the process is somewhat old-fashioned ( >0.5 micron), then there is a chance. XC3000L used to consume <50 microamps, which is an acceptable (barely!) value. If the manufacturer did not pay special attention, and does not indicate so in the data sheet, your hopes are slim. For all really up-to-date devices with geometries below 0.2 microns, (or 200 nanometers as it is more fashionably called), there is no hope. The inherent so-called leakage current is milliamps ( and more). But you can always try it out by measuring, both at room and at slightly elevated temperature... Peter Alfke, Xilinx Applications ==================================== Chris Cowdery wrote: > I am considering using a lithium battery on a board instead of a > config device to enable my Altera FLEX10KA to retain its > configuration. > > Has anyone any idea of the absolute min quiescent current I can expect > a 10KA to draw? > > Thanks, > > Chris. ###### From: kayrock66@yahoo.com (Jay) Newsgroups: comp.arch.fpga Subject: Re: Using a battery instead of Config device Date: 7 Mar 2002 10:40:13 -0800 Organization: http://groups.google.com/ Lines: 45 Message-ID: References: <685ae314.0203060928.16ef5215@posting.google.com> <3C86D98F.1305708A@earthlink.net> NNTP-Posting-Host: 208.178.183.62 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1015526413 30109 127.0.0.1 (7 Mar 2002 18:40:13 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 7 Mar 2002 18:40:13 GMT Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!newsfeed.icl.net!newsfeed1.cidera.com!Cidera!news-hog.berkeley.edu!ucberkeley!newsfeed.stanford.edu!postnews1.google.com!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:15038 The leakage current will vary dramatically (AKA exponentially) with temperature. The 300uA numbers in the datasheet are for room temp only. Also, all your inputs must be driven to one of the supply rails, anything between VDD and VSS on an input will leak juice and drain your battery. The outputs cannot be left driving anything except a FET gate. If you haven't been through this game before, it can really be an task trying to patch all the leaks. Did something similar for a USB device trying to make the 500uA standby requirement. Regards Peter Alfke wrote in message news:<3C86D98F.1305708A@earthlink.net>... > I can obviously not speak for Altera, but here are some general > observations: > > If the manufacturer made sure that all dc-consuming utilities are turned > off as soon as the normal Vcc disappears, and if the process is somewhat > old-fashioned ( >0.5 micron), then there is a chance. XC3000L used to > consume <50 microamps, which is an acceptable (barely!) value. > > If the manufacturer did not pay special attention, and does not indicate > so in the data sheet, your hopes are slim. > For all really up-to-date devices with geometries below 0.2 microns, (or > 200 nanometers as it is more fashionably called), there is no hope. The > inherent so-called leakage current is milliamps ( and more). > > But you can always try it out by measuring, both at room and at slightly > elevated temperature... > > > Peter Alfke, Xilinx Applications > ==================================== > Chris Cowdery wrote: > > > I am considering using a lithium battery on a board instead of a > > config device to enable my Altera FLEX10KA to retain its > > configuration. > > > > Has anyone any idea of the absolute min quiescent current I can expect > > a 10KA to draw? > > > > Thanks, > > > > Chris.