PADS Layout Output Files (with videos)

Overview

Mason can output to a ASCII file format which can be read in by the PADS Layout program. The data in the PCB section of the primitive XML files can be used to construct microstrip lines; devices can also have a standard decal defined, such as for resistors or amplifiers. Mason will properly place the microstrip lines and "smart" footprints that are contiguously connected. Check out these comments on Smart Footprints. You can learn how to create the smart footprint here.

Several ASCII output files are possible. One treats each microstrip component as a separate device and also outputs the pre-defined decals (like 0402 for lumped resistors). This is typically used when TinyCAD is your principle schematic tool. The second and third file outputs what is effectively a single decal which can be defined in concert with an external schematic capture tool (like DxDesigner).

When the combined decal is used, the following nodes will become terminals, which will be the accessible ports in the new decal: any node on a port, any node on the ground net, and any node with a Layout_Terminal (looks similar to a Port, but not part of the simulation).

1. Create a PADS ASCII file using the given file name
  1. Mason actually outputs two files
    1. one treats each microstrip component as a separate device and also outputs the pre-defined decals (like 0402 for lumped resistors)
    2. The second file outputs what is effectively a single decal which can be defined in concert with an external schematic capture tool (like DxDesigner); appends "combined.asc" to the file name.

As of version 4.5, you can output PADS layout files from subcircuits

Under the flag block, "Show" the PADS-ASCII parameter to output a combination of primitive components and pre-defined decals in the layout tool (such as an 0402), plus the combined single decal
Under the flag block, "Show" the PADS-INDIVIDUAL parameter to output just the primitive/pre-defined file (it will not output the ASCII file which combines all of the primitive parts into a single decal)
Under the flag block, "Show" the PADS_COMBINED2 parameter to output the improved version of the single decal ASCII file

Comments on PADS_COMBINED2 (Improved decal)

The improved decal tool provides greater control over the number of terminals created, which helps with integration into a schematic tool. The first terminals will be the RF ports (_Port1 will be terminal 1, _Port2 will be terminal 2); the next terminals will be defined using the Schematic_Terminals, which also use the _Port? reference designator but instead of defining an impedance define a terminal number; the next terminals will be the ground nodes (so they can be individually tied down); finally, all the other copper pieces will be lumped into a separate terminal.

Part of schematic showing schematic terminal (on the 5V bus)

One Minute Video

(This video is only useful if you want to see that it works- check out the videos below to see how to do it)

In Depth of Layout Generation

Automatically creating a layout using a Circuit Mason electrical design

Advanced Techniques in Layout Generation

Shows advanced layout generation features of Mason. Goes over how the same schematic can be used for RF simulation, while still containing the digital and analog components needed for the full layout.