Go to IPC http://www.ipc.org/contentpage.asp?Pageid=4.6 and download the IPC-7351 Land Pattern Viewer. Once installed on your computer lookup QFN50P800X800-57V2N for land pattern for a JEDEC MO-220-VLLD-2. I have found that these parts are subject to solder joint cracking but it depends a lot on your environment. Cheers Donald Kyle At 08:06 AM 12/2/2005, you wrote: >Best use the silicon datasheet in order to get the actual tab dimensions - >MO-220 only gives min/max dimensions which are >extremely wide in order to allow the actual tab to be matched to the die >or allow flexibility. >If AD do not give a recommended footprint (no doubt for liability) the >best recourse would be assembly house preferences or >IPC-7351. > >Allegro footprint attached. No liability accepted! > >Best Regards > >David Greig >______________________________ >GigaDyne Ltd >Buchan House >Carnegie Campus >Dunfermline KY11 8PL >United Kingdom >t: +44 (0)1383 624 975 >www.gigadyne.co.uk >______________________________ > >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Brooks,Bill >Sent: 01 December 2005 20:52 >To: [log in to unmask] >Subject: [TN] 56 pin LFCSP footprint > >I have an Analog Devices part, 56-lead Lead Frame Chip Scale Package LFCSP >with an 8X8mm body CP-56, supposed to be compliant >with JEDEC MO-220-VLLD-2. > >Having a tough time locating a recommended footprint for this one... >Any help? > >Also any issues with mounting? Since this is a direct to board soldered >device, it may be subject to CTE mismatches and the >like... anyone have experience with any soldering or reliability issues >with assembling this part to a fiberglass/epoxy board? > >Here's a link to the part description >http://www.analog.com/UploadedFiles/Packages/352655155839944545242119821CP_5 >6.pdf ><http://www.analog.com/UploadedFiles/Packages/352655155839944545242119821CP_ >56.pdf> > >Best regards, > > >Bill Brooks > >--------------------------------------------------- >Technet Mail List provided as a service by IPC using LISTSERV 1.8e To >unsubscribe, send a message to [log in to unmask] with >following text in the BODY (NOT the subject field): SIGNOFF Technet To >temporarily halt or (re-start) delivery of Technet send >e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE >mailing per day of all the posts: send e-mail to >[log in to unmask]: SET Technet Digest Search the archives of previous posts >at: http://listserv.ipc.org/archives Please visit IPC >web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional >information, or contact Keach Sasamori at >[log in to unmask] or 847-615-7100 ext.2815 >----------------------------------------------------- >-- >Virus scanned by Lumison. > >--------------------------------------------------- >Technet Mail List provided as a service by IPC using LISTSERV 1.8e >To unsubscribe, send a message to [log in to unmask] with following text in >the BODY (NOT the subject field): SIGNOFF Technet >To temporarily halt or (re-start) delivery of Technet send e-mail to >[log in to unmask]: SET Technet NOMAIL or (MAIL) >To receive ONE mailing per day of all the posts: send e-mail to >[log in to unmask]: SET Technet Digest >Search the archives of previous posts at: http://listserv.ipc.org/archives >Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 >for additional information, or contact Keach Sasamori at [log in to unmask] or >847-615-7100 ext.2815 >----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------