From: "news.dlr.de" Newsgroups: comp.arch.fpga Subject: 1,5V power supply? Date: Tue, 19 Mar 2002 15:41:30 +0100 Organization: DLR Lines: 21 Message-ID: NNTP-Posting-Host: hvenus.ws.ba.dlr.de X-Trace: news.go.dlr.de 1016548590 527 129.247.219.3 (19 Mar 2002 14:36:30 GMT) X-Complaints-To: usenet@news.dlr.de NNTP-Posting-Date: 19 Mar 2002 14:36:30 GMT X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!fr.clara.net!heighliner.fr.clara.net!newsfeed.hanau.net!news-fra1.dfn.de!news-koe1.dfn.de!news!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:15484 Hello all, I am designing a VIRTEX-II board running at up to 80 MHz. I use the 1M gates FF896 housed devices but prepared the layout for FF1152 6M gates device. There are several parallel operating data paths doing image processing. How should I prepare the 1.5V core voltage? There are operation modes which need some watts. That means, the power supply has to deliver several amperes (voltage drop over layout??). My power source could be 3.3V or 5V of the cPCI backplane. Is a linear converter OK? Is a step down converter recommended? Are there reference designs available on the net? Thank you for your support. Holger Venus ###### From: "Tim" Newsgroups: comp.arch.fpga Subject: Re: 1,5V power supply? Date: Tue, 19 Mar 2002 15:21:14 -0000 Message-ID: <1016555651.937.0.nnrp-14.9e9832fa@news.demon.co.uk> References: NNTP-Posting-Host: tile.demon.co.uk X-NNTP-Posting-Host: tile.demon.co.uk:158.152.50.250 X-Trace: news.demon.co.uk 1016555651 nnrp-14:937 NO-IDENT tile.demon.co.uk:158.152.50.250 X-Complaints-To: abuse@demon.net X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Lines: 32 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!newsfeed.icl.net!dispose.news.demon.net!news.demon.co.uk!demon!tile.demon.co.uk!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:15514 Even dropping from 3.3V, you will need a big heat sink if you go the linear route and expect to use any substantial current in the FPGA. Use a switcher. Xilinx recomment the Elantec devices. Other sources include Linear Technology, Texas Instruments, and Maxim. There are others as well. "news.dlr.de" wrote in message news:a77ide$gf$1@news.go.dlr.de... > Hello all, > I am designing a VIRTEX-II board running at up to 80 MHz. > I use the 1M gates FF896 housed devices but prepared the layout for > FF1152 6M gates device. > There are several parallel operating data paths doing image processing. > How should I prepare the 1.5V core voltage? > There are operation modes which need some watts. > That means, the power supply has to deliver several amperes > (voltage drop over layout??). > My power source could be 3.3V or 5V of the cPCI backplane. > > Is a linear converter OK? > Is a step down converter recommended? > Are there reference designs available on the net? > > Thank you for your support. > > Holger Venus ###### From: Theron Hicks Newsgroups: comp.arch.fpga Subject: Re: 1,5V power supply? Date: Tue, 19 Mar 2002 12:25:11 -0500 Organization: Michigan State University Lines: 12 Message-ID: <3C977477.48D743D1@egr.msu.edu> References: NNTP-Posting-Host: dfti.egr.msu.edu Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 4.77 [en] (Windows NT 5.0; U) X-Accept-Language: en Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!newsfeed.icl.net!news.maxwell.syr.edu!elk.ncren.net!nntp.upenn.edu!msunews!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:15475 I personally like the LT1764 series part from linear technology. Theron Hicks Manfred Kraus wrote: > I had to make the same decision 5 days ago and will use the > MICREL part: MIC35101-1.5BR > It's a LDO regulator that delivers 1.5V @ 5 Amp. > Maybe it will also work for you. > > -Manfred ###### From: kayrock66@yahoo.com (Jay) Newsgroups: comp.arch.fpga Subject: Re: 1,5V power supply? Date: 19 Mar 2002 14:13:50 -0800 Organization: http://groups.google.com/ Lines: 31 Message-ID: References: NNTP-Posting-Host: 208.178.183.62 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1016576030 26841 127.0.0.1 (19 Mar 2002 22:13:50 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 19 Mar 2002 22:13:50 GMT Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.mailgate.org!newsfeed.icl.net!netnews.com!xfer02.netnews.com!newsin.iconnet.net!feed.tor.primus.ca!feed.nntp.primus.ca!newsfeed-tor.nnrp.ca!newsfeed-tor.nnrp.ca!news.gv.tsc.tdk.com!sn-xit-02!supernews.com!postnews1.google.com!not-for-mail Xref: chonsp.franklin.ch comp.arch.fpga:15576 Either supply technology will work but your choice will depend on other parameters such as heat, available current in the 3.3 and 5v supplies, cost, complexity, etc. The buck converter is more expensive and complex than a linear although the suppliers of these chips provide excellent example circuits. The linear solution will use more than twice the power (and heat) of the switching one. You won't drop enough voltage in the layout to matter because you will be using power planes. Regards "news.dlr.de" wrote in message news:... > Hello all, > I am designing a VIRTEX-II board running at up to 80 MHz. > I use the 1M gates FF896 housed devices but prepared the layout for > FF1152 6M gates device. > There are several parallel operating data paths doing image processing. > How should I prepare the 1.5V core voltage? > There are operation modes which need some watts. > That means, the power supply has to deliver several amperes > (voltage drop over layout??). > My power source could be 3.3V or 5V of the cPCI backplane. > > Is a linear converter OK? > Is a step down converter recommended? > Are there reference designs available on the net? > > Thank you for your support. > > Holger Venus