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Component zero Orientation A or B?

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AB_Regin View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AB_Regin Quote  Post ReplyReply Direct Link To This Post Topic: Component zero Orientation A or B?
    Posted: 03 Oct 2018 at 6:37am
What component zero orientation does your POD follow?

It seems like "level B" for most of the package types, but a demo of DFN-4 seems like a "level A"?

 
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Tom H View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 03 Oct 2018 at 7:09am
The 4-Pin DFN has a Right Mouse Button "Reorder Pins" option. 

The default 4-Pin DFN should be changed so the the default part looks like this - 
 

 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote AB_Regin Quote  Post ReplyReply Direct Link To This Post Posted: 03 Oct 2018 at 11:52pm
Hi Tom,

Your example footprint with the pin 1 to the low left is with IEC 61188-7 “Level B” Zero Orientation and mine straight out from Library Expert, is with IEC 61188-7 “Level A” Zero Orientation?

My question is what zero orientation level your footprint library follow?
Or more specific; when using POD and Library Expert to create footprints for our cad-system, can I expect to get any of these orientation levels and that I have to be observant and check it by myself which level it has and maybe rearrange the pin locations if our footprints shall follow the level B? 

We expected to be able to use all POD:s almost straight out of the box and only have to adjust cosmetic stuff...

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Post Options Post Options   Thanks (1) Thanks(1)   Quote AB_Regin Quote  Post ReplyReply Direct Link To This Post Posted: 04 Oct 2018 at 12:58am
I can add some more information after some searching..
I found this old topic: 

At that time you Tom said that the Library Expert follows the IPC 7315C and Level B zero rotation, but that does not seem to be the case with the DFN-4?

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Post Options Post Options   Thanks (0) Thanks(0)   Quote AB_Regin Quote  Post ReplyReply Direct Link To This Post Posted: 04 Oct 2018 at 1:17am
And more...
I found this document, in which the DFN-4 is described as an oscillator (this is just a matter of a different 3D Body i guess):
https://www.pcblibraries.com/Products/FPX/UserGuide/download/Library%20Expert%20Surface%20Mount%20Families.pdf

Here in this document it shows the correct rotation for level B, but your library expert outputs it as level A!


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Post Options Post Options   Thanks (1) Thanks(1)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 04 Oct 2018 at 8:23am
I see now what you are referring to. 

I created the documentation, so now I have to find some 4-pin DFN parts and see what the typical pin numbering scheme is for Antenna, Capacitor, Crystal, Diode, Filter, Inductor, IC, Oscillator (the most used family for this package), Resistor & Transistor. 

Thank you for reporting this issue.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote AB_Regin Quote  Post ReplyReply Direct Link To This Post Posted: 04 Oct 2018 at 10:37pm
Thanx Tom!
I can help you by telling that I discovered this issue after POD download of this one:

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Post Options Post Options   Thanks (0) Thanks(0)   Quote ransonjd Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2020 at 1:00pm
Hi,

I'm noting that 4-pin DFNs still follow "A" orientation and not "B" orientation. What's the motivation for this difference from other 4-pin components?

Thanks!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2020 at 1:15pm
It's because the "D" dimension is normally larger than the "E" dimension. 

Our software programmer didn't read our documentation. Confused

Not sure if IPC-7351C will ever adopt the Orientation B concept to align with the IEC 61188-7 Standard which lists both A & B orientations. 

I'm not sure if IPC-7351C will ever be released. The chairman Karen McConnell just stepped down after 20 years and the subcommittee is losing interest. 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 27 Feb 2020 at 1:17pm
I forgot to mention the main reason. 

Unlike most component families, the 4-pin DFN has multiple pin configurations and Pin 1 can be in different locations. 

So there really is no Zero Orientation for the 4-pin DFN. 

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