PCB Libraries Forum : SMPC (TO-277A) made out of DFN standard https://www.PCBLibraries.com/forum/ Wed, 15 Apr 2026 00:51:52 +0000 Fri, 25 Feb 2022 10:22:06 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=3067 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[SMPC (TO-277A) made out of DFN standard : So I probably missed the rounded...]]> https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12252.html#12252 Author: zentekfr
Subject: 3067
Posted: 25 Feb 2022 at 10:22am

So I probably missed the rounded rectangle option.
Then a webcast is welcome! I will send you an e-mail.
]]> Fri, 25 Feb 2022 10:22:06 +0000 https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12252.html#12252 <![CDATA[SMPC (TO-277A) made out of DFN standard : In FP Designer you have 100% control...]]> https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12248.html#12248 Author: Tom H
Subject: 3067
Posted: 24 Feb 2022 at 10:42am

In FP Designer you have 100% control of the pad stacks like Rounded Rectangle Pads and Pad Shapes. 

All non-standard package footprints should be created in FP Designer. 

This is not a 3-Tier Density footprint. Only the mfr. recommended pattern will work correctly. 

If you need FP Designer training, we can do a quick webcast so I can show you some great features. 

]]> Thu, 24 Feb 2022 10:42:08 +0000 https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12248.html#12248 <![CDATA[SMPC (TO-277A) made out of DFN standard : Hello Tom,Of course it&#039;s...]]> https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12247.html#12247 Author: zentekfr
Subject: 3067
Posted: 24 Feb 2022 at 12:58am

Hello Tom,

Of course it's not a DFN. But as soon as I use the FP Designer, I'm losing much of the features of Footprint Expert (3-tier density system, rounded rectangle pads, pad shapes drawing, Master options for batch generation, ...).
That's why I considered building it from a known standard package.

Thanks for your answer Wink
Justin
]]> Thu, 24 Feb 2022 00:58:18 +0000 https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12247.html#12247 <![CDATA[SMPC (TO-277A) made out of DFN standard : The Vishay TO-277A Case Code is...]]> https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12246.html#12246 Author: Tom H
Subject: 3067
Posted: 23 Feb 2022 at 9:45am

The Vishay TO-277A Case Code is not a 3-pin DFN component family. 

This footprint must be created in FP Designer.  

There are 34 Vishay part numbers on www.pcblibraries.com/POD that have the TO-277A Case Code. 

Try this one - uploads/3/Vishay_TO-277A.zip

]]> Wed, 23 Feb 2022 09:45:58 +0000 https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12246.html#12246 <![CDATA[SMPC (TO-277A) made out of DFN standard : I add the drawings and datasheet...]]> https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12245.html#12245 Author: zentekfr
Subject: 3067
Posted: 23 Feb 2022 at 6:06am

I add the drawings and datasheet for reference: https://www.vishay.com/docs/89335/ar4pm.pdf

]]> Wed, 23 Feb 2022 06:06:44 +0000 https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12245.html#12245 <![CDATA[SMPC (TO-277A) made out of DFN standard : Hello,In the process of building...]]> https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12244.html#12244 Author: zentekfr
Subject: 3067
Posted: 23 Feb 2022 at 3:57am

Hello,

In the process of building a footprint for a SMPC component (standardized against JEDEC TO-277A), I found that a 3-pin DFN could do the job. The obtained land pattern is very close to the manufacturer's recommended footprint. Of course the pins should be reordered/renamed.
Is my idea of building this part out of a DFN3 good? Not advisable? And why?


Thanks!
]]> Wed, 23 Feb 2022 03:57:35 +0000 https://www.PCBLibraries.com/forum/smpc-to277a-made-out-of-dfn-standard_topic3067_post12244.html#12244