From: pvm <pvm...@gm...> - 2007-12-16 22:24:50
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I'm looking at page 20 of this data sheet, http://focus.ti.com/lit/ds/symlink/sn74lvc1t45.pdf I'm a little confused as to what the fractions are saying. Is that a tolerance range? and what does the 6x mean in front of the 0.50/0.25 fraction denoting the pin width. While I'm on the topic I'm trying to design my first board with Eagle CAD to interface with the Gumstix. Any tips are appreciated. Thanks, -Pete -- View this message in context: http://www.nabble.com/How-do-you-read-the-mechanical-measurements...-tp14367166p14367166.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Andrew M. <mac...@gm...> - 2007-12-16 23:18:41
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Hi Pete, The 6x just means that this measurement is the same for all 6 pins. The "fractions" actually show the maximum and minimum possible values, so 0,50 / 0,25 means that the pin size can vary somewhat but is guaranteed to be between 0.50 and 0.25 mm wide. Hope that helps, Andrew On 16/12/2007, pvm <pvm...@gm...> wrote: > > > I'm looking at page 20 of this data sheet, > http://focus.ti.com/lit/ds/symlink/sn74lvc1t45.pdf > > I'm a little confused as to what the fractions are saying. Is that a > tolerance range? and what does the 6x mean in front of the 0.50/0.25 > fraction denoting the pin width. > > While I'm on the topic I'm trying to design my first board with Eagle CAD > to > interface with the Gumstix. Any tips are appreciated. > > Thanks, > -Pete > -- > View this message in context: > http://www.nabble.com/How-do-you-read-the-mechanical-measurements...-tp14367166p14367166.html > Sent from the Gumstix mailing list archive at Nabble.com. > > > ------------------------------------------------------------------------- > SF.Net email is sponsored by: > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services > for just about anything Open Source. > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: pvm <pvm...@gm...> - 2007-12-16 23:44:37
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Andrew MacIsaac-2 wrote: > > The 6x just means that this measurement is the same for all 6 pins. The > "fractions" actually show the maximum and minimum possible values, so 0,50 > / > 0,25 means that the pin size can vary somewhat but is guaranteed to be > between 0.50 and 0.25 mm wide. > It does thanks. So when I am creating the part in the Eagle library should I be making it using the maximum dimensions? or is there some general rule to follow? -- View this message in context: http://www.nabble.com/How-do-you-read-the-mechanical-measurements...-tp14367166p14367980.html Sent from the Gumstix mailing list archive at Nabble.com. |
From: Andrew M. <mac...@gm...> - 2007-12-17 01:16:03
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I've never created a part in Eagle so I can't offer any advice about that specifically. In general I just assume that the component will fall in the middle of the range, but make my PCB pads large enough to get a good connection at the two extremes. SOT23 is also quite a common package, so there may already be a footprint somewhere that you can use. Andrew On 16/12/2007, pvm <pvm...@gm...> wrote: > > > > Andrew MacIsaac-2 wrote: > > > > The 6x just means that this measurement is the same for all 6 pins. The > > "fractions" actually show the maximum and minimum possible values, so > 0,50 > > / > > 0,25 means that the pin size can vary somewhat but is guaranteed to be > > between 0.50 and 0.25 mm wide. > > > > It does thanks. So when I am creating the part in the Eagle library should > I > be making it using the maximum dimensions? or is there some general rule > to > follow? > > > -- > View this message in context: http://www.nabble.com/How-do-you-read-the-mechanical-measurements...-tp14367166p14367980.html > > Sent from the Gumstix mailing list archive at Nabble.com. > > > ------------------------------------------------------------------------- > SF.Net email is sponsored by: > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services > for just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > gumstix-users mailing list > gum...@li... > https://lists.sourceforge.net/lists/listinfo/gumstix-users > |
From: Dave H. <dhy...@gm...> - 2007-12-17 05:14:59
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Hi Pete, > Andrew MacIsaac-2 wrote: > > > > The 6x just means that this measurement is the same for all 6 pins. The > > "fractions" actually show the maximum and minimum possible values, so 0,50 > > / > > 0,25 means that the pin size can vary somewhat but is guaranteed to be > > between 0.50 and 0.25 mm wide. > > > > It does thanks. So when I am creating the part in the Eagle library should I > be making it using the maximum dimensions? or is there some general rule to > follow? When I do stuff in Eagle, whenever possible, I steal the layout from somebody else's part. For example, in the zetex.lbr file, you'll find a SOT23-6 package, which I think is what you want. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |
From: Dave H. <dhy...@gm...> - 2007-12-17 07:39:05
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Hi Andrew, > When I do stuff in Eagle, whenever possible, I steal the layout from > somebody else's part. > > For example, in the zetex.lbr file, you'll find a SOT23-6 package, > which I think is what you want. I found this tutorial to be quite good, especially since it covers how to do copy & paste in Eagle, which is quite non-intuitive. <http://myhome.spu.edu/bolding/EE4211/EagleTutorial4.htm> -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |