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Peter Johnson
United Kingdom
511 Posts |
 Posted - 01 Feb 2006 : 13:10:50
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There are 2 in sm.psl. When they were originally created (probably in 1992) the pin out was correct, but the industry standard has changed since then. Use with care!
Peter Johnson
Technical Support
Number One Systems |
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chris.mullen@ncl.ac.uk
2 Posts |
Posted - 06 Dec 2006 : 06:10:21
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quote:
Originally posted by Peter Johnson
There are 2 in sm.psl. When they were originally created (probably in 1992) the pin out was correct, but the industry standard has changed since then. Use with care!
Peter Johnson
Technical Support
Number One Systems
Hi Peter,
am I correct in thinking that that footprints for QFP64 (QFP64B, QFP64C and QFP64 in libraries Qbsm, Qcsm & Qsm) are incorrect (since they are not square)? Also can you explain the difference between the 3 libraries?
Thankyou,
Chris |
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Peter Johnson
United Kingdom
511 Posts |
Posted - 06 Dec 2006 : 06:45:09
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The surface mount devices supplied as standard are almost all taken from the first release of the IPC-SM782 standard, which was pre-millenium. At the time, rectangular profiles were more common than square, but the position has changed.
Footprints using the up to date standard are available in the IPC-SM supplementary library.
All the footprints are physically identical and number anticlockwise, but the pin 1 position varies:
QSM is at the corner with the dot.
QBSM is at the centre f the side anticlockwise from the dot.
QCSM is at the centre of the side clockwise from the dot, always a rare configuration, and now probably obsolete.
Peter Johnson
Technical Support
Number One Systems |
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chris.mullen@ncl.ac.uk
2 Posts |
Posted - 06 Dec 2006 : 07:27:51
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quote:
Originally posted by Peter Johnson
...Footprints using the up to date standard are available in the IPC-SM supplementary library....
Thanks for your help and prompt response. I will have to consider purshasing the IPC-SM library.
Chris |
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Topic |
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SOT23 footprints