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Allegro Extra pins and Missing Pins

salasidis

I am new to Allegro, and have a problem with PCB Footprints for certain components.

 

For example,

 

A) one component mounts on a Dip16 footprint, but only has 4 pins (pin 1,8,9,16).

 

B) A diode uses a SOT-23 package with 3 pins, but only 2 pins are required.

 

How does one force Allegro to ignore missing pins in the schematic that are not required (example A).

 

I have "fixed" this by defining in my Orcad CIS part schematic invisible zero length pins that are not required (ie define the other 12 pins in example A, or create a new diode symbol with an extra unused pin.

 

Is there a better way?

 

 

(netrev.lst output below

 

ERROR(SPMHNI-196): Symbol 'SOT65P210X110-3N' for device 'DIODE TS_SOT65P210X110-3N_DISCR' has extra pin '3'.

#2   WARNING(SPMHNI-192): Device/Symbol check warning detected.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '2'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '3'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '4'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '5'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '6'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '7'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '9'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '11'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '12'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '13'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '14'.

ERROR(SPMHNI-196): Symbol 'DIP16' for device 'CPC1945G_DIP16_DISCRETE_CPC1945' has extra pin '15'.

Parents

  • I'm a little puzzled to know what is precisely the problem. When you say "one component mounts on a Dip16 footprint, but only has 4 pins (pin 1,8,9,16)" do you mean:

    (a) the package has all 16 physical pins but only 4 are used (the other 12 not connected)

    (b) the package has the same outline as a DIP16 but has only 4 physical pins (those at the corners)?

    If it's (a), you should use the usual DIP16 footprint and add the NC property for the unconnected pins in Capture, as has already been explained by Mitch.

    If it's (b), you should edit the footprint in PCB Editor to remove the non-existent pins, save it under a new name, and use this new name for the footprint in Capture. Follow the instructions in algrolibdev, which are clear.(It's easy to make a completely new footprint using the New Symbol Wizard provided that you have identified the padstacks first.)

    I have no idea whether pin number have to be sequential from 1 (1, 2, 3, etc); every package that I have ever used has been numbered this way and I never worried about it! It seems an obvious convention to follow.The pin numbers used by the symbol in Capture must match those on the package used in PCB Editor.

    Good luck, John

Reply

  • I'm a little puzzled to know what is precisely the problem. When you say "one component mounts on a Dip16 footprint, but only has 4 pins (pin 1,8,9,16)" do you mean:

    (a) the package has all 16 physical pins but only 4 are used (the other 12 not connected)

    (b) the package has the same outline as a DIP16 but has only 4 physical pins (those at the corners)?

    If it's (a), you should use the usual DIP16 footprint and add the NC property for the unconnected pins in Capture, as has already been explained by Mitch.

    If it's (b), you should edit the footprint in PCB Editor to remove the non-existent pins, save it under a new name, and use this new name for the footprint in Capture. Follow the instructions in algrolibdev, which are clear.(It's easy to make a completely new footprint using the New Symbol Wizard provided that you have identified the padstacks first.)

    I have no idea whether pin number have to be sequential from 1 (1, 2, 3, etc); every package that I have ever used has been numbered this way and I never worried about it! It seems an obvious convention to follow.The pin numbers used by the symbol in Capture must match those on the package used in PCB Editor.

    Good luck, John

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