Hi, Le Wed, 20 Oct 2010 12:01:05 +0800, Adam Wang <[email protected]> a écrit : > > * You do not need to add that many 100uF capacitors on the DRAM. > > It's mostly high frequency noise that we are filtering. Use only > > one extra 100uF per chip instead of 4. > > > > Ok, will only remain C248 & C240 100uF. So the all other 100nF > capacitors we added just keep them there, > Since those C162, C166, C159 and C160 you added another one 100nF > capacitor each in parallel. > http://www.milkymist.org/wiki/index.php?title=RC1_signal_integrity_measurements#Setup
OK > One thing,could you send me which vendor and vendor's part number you > used for http://www.vishay.com/docs/82090/tsop48xx.pdf , I found even > with the same P/N searched on google, it may get a same part > number TSOP4838 but its supply voltage is 4.5~5.5V. On the datasheet link that you sent (and on most others that I found), it's 2.7-5.5V. But on this older one: http://www.innovativeelectronics.com/innovative_electronics/download_files/datashet/TSOP48XX.pdf it's 4.5-5.5V indeed... Nice! They made a new part with a wider supply voltage without updating the P/N. On some datasheet the 2.7V parts are described as "New" TSOP48xx. So, either: * make sure you order the "New" ones. The working parts that I got were coming from Vishay Sample Service, so they are most probably "New" TSOP48xx. -or- * try a sample of the TSOP34838 that you mentioned on your MM1 prototype and use these if they work. I have kept the "broken" TSOP4838 that were installed on the boards you sent me... maybe those were only the older 4.5V parts. > I sourced Hexagonal Threaded Space and Plastic Fastener for M1 board, > please check: > http://en.qi-hardware.com/wiki/Milkymist_One_run_2_schedule#Packaging_Parts_Accessaries > The threaded space<P/N: HTS-308> is 8mm height with 3mm, > http://www.kss.com.tw/e4k/e4-11/C1111-1.asp > If it's OK, I'll change the innner diameter of 4 through holes on > board from 3 to 3.3mm for example. Ok, good! Sébastien _______________________________________________ http://lists.milkymist.org/listinfo.cgi/devel-milkymist.org IRC: #milkym...@freenode Twitter: www.twitter.com/milkymistvj
