SOT223 pin numbering
Printed From: PCB Libraries Forum
Category: PCB Footprint Expert
Forum Name: Questions & Answers
Forum Description: issues and technical support
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=902
Printed Date: 22 Nov 2024 at 5:23pm
Topic: SOT223 pin numbering
Posted By: hmartins
Subject: SOT223 pin numbering
Date Posted: 25 Mar 2013 at 8:56am
Hi.
SOT223 produces footprints with pin numbers 1 to 4 while Capture expects for pins 0 to 3.
I understood how to rearrange pin order, but can't find a way to renumber them 0 to 3.
Thanks
Martins
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Replies:
Posted By: Tom H
Date Posted: 25 Mar 2013 at 12:55pm
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I've been doing PCB design since 1974 and I never heard of "Pin 0" before. Is that new?
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Posted By: hmartins
Date Posted: 25 Mar 2013 at 6:08pm
Please note these pin numbers I refer are internal Orcad Capture pin numbers, not manufacturer numbers or the usual way we count pins.
I don't have the system here, but as much as I remember it is mosfets NDT3055 and NDT2955. Same for SIPC14N60 (also mosfet).
I suppose from Orcad default libs.
Meanwhile I found out that in script file there is something like "NEXTPIN 1", that I changed to "NEXTPIN 0" and rerun batch file.
It seems OK now. Capture's 'see footprint' (just by memory, don't forget) gives correct result.
If you need more details I can give them tomorrow.
Martins
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Posted By: hmartins
Date Posted: 26 Mar 2013 at 2:49am
Ok.
Orcad Capture 'sees' AD8051 as having pins 2, 3, 4, 6, 7 for -, +, V-, Out, V+.
Orcad Capture 'sees' NDT8055 and 14N60 (mosfets) as havin pins 0, 1, 2 for s, g, d.
Orcad Capture 'sees' H11AV1 (optocoupler) as having pins 1, 2, 4, 5, 6 for Anode, Cathode, E, B, C.
Regards
Hmartins
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Posted By: hmartins
Date Posted: 26 Mar 2013 at 2:56am
I apparently solved the problem the following way:
In SOT223-4.scr in:
# Pin Generation
add pin
setwindow Form.mini
FORM mini pad_name r197_89
FORM mini next_pin_number 0
rotate
iangle 270
FORM mini pintype_mechanical NO
FORM mini offsetx 0
FORM mini offsety 0
setwindow pcb
pick -2.3 -3.025
pick 2.3 -3.025
pick 0 -3.025
setwindow Form.mini
FORM mini pad_name r197_319
iangle -180
setwindow pcb
pick 0 3.025
done
I changed the bolded line to:
FORM mini next_pin_number 0
Them I rerun he batch file.
It seems to have solved the problem (as time goes by it will become clear).
Software should include an easy way to define first pin number.
Martins
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Posted By: Tom H
Date Posted: 26 Mar 2013 at 6:52am
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Martins, Why don't you rename the SOT223 Pins -, +, V-, Out, V+ or S, D, G or E, B, C? Just select any pin and "Right Mouse Button > Properties" and enter the new Pin Name value.
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Posted By: hmartins
Date Posted: 26 Mar 2013 at 7:29am
No, no. I did not rename anything.
The above list with three component
types is just an example of how different components (and packages) are
arranged in terms of pin numbers.
AD8051 is indeed AD8531 (I apologize for the mistake) and is SOIC8.
NDT8055 and 14N60* (mosfets) are SOC223
H11AV1 (optocoupler) is DIP6.
In Orcad Capture, the mosfets NDT8055 and 14N60 have pin numbers from 0 to 2 whose names are: s, g, d respectively.
Note*
14N60 was indeed TO220 but for other peculiar reason I created a 'special' SOC223 so that I can solder TO220 as if it would be an SMD device. Anyway, in Orcad Capture the pin numbering is the sae as mosfet NDT8055.
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Posted By: hmartins
Date Posted: 26 Mar 2013 at 7:43am
"Just select any pin and "Right Mouse Button > Properties" and enter the new Pin Name value."
I can't. It doesn't allow me to change pin numbers (inside capture) and, as much as I know, if I do that PSpice will argue that pins are messed. I think PSpice pin number models must correspond to pin capture pin numbers.
May be I can change by Right Mouse->Edit Part, but I thik I will mess things with PSpice.
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Posted By: rdl86626
Date Posted: 27 Mar 2013 at 7:14am
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You can change orcad capture pin numbers by editing the part. click on the part, right mouse button, edit part. When you leave out of edit you can save the change for all parts or just the one. Hope this helps.
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Posted By: hmartins
Date Posted: 27 Mar 2013 at 7:26am
I can change Orcad Capture pin numbers editing the part but then later PSpice models pins will not correspond to the pins in diagram and issue an error, somelhing like pin_number_mismatch.
Seems to me that you should also allow selection from 0, not just from 1.
I solved the problem several times already modifying the script before running the bat file.
As example, in SOT223-4.scr I modified the bolded line:
# Pin Generation
add pin
setwindow Form.mini
FORM mini pad_name r197_89
FORM mini next_pin_number 0
Regards
Martins
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Posted By: hmartins
Date Posted: 27 Mar 2013 at 8:47am
Correction,
You are right, PSpice doesn't care if I change pin numbers in Capture Edit_Part. I had that problem in the past but may be for other reason or in the presence of some other circumstances.
I tested and you are right. I apologize.
Regards
Martins
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