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TinyCAD

Creating, Running, and Plotting Circuits


Overview

This page features may important points where TinyCAD has been modified to work with Mason.  Even if you are already familiar with TinyCAD, you should still read through this page.

TinyCAD is a schematic capture tool that has been modified to work with Mason.  This quick start video  goes over the basics of using the TinyCAD interface.  Several libraries of parts has been specifically developed to work with Mason. This library is not completely comprehensive; however it is relatively simple to develop new parts.

Mason (and several helper programs) can be run from the GUI, and most features are available through library components. Most devices should be straight forward to place and use. Nets can be named for compatibility with combining DxDesigner and Mason designs in PADS Layout.

The TinyCAD for Mason has been modified in several key ways from the original code beyond the Mason toolbar.
  • As of version 4.4, one can left click in the text box for the "Tool Option" dialog box used for parts and the cursor will go to that location.  (To be honest, the first revision- 4.4- may be a little off; I'm having issues mapping the logical units to pixels).  If you right click then all of the text will be selected in that box.
  • As of version 4.4, a PrimCalc button has been added to the "Tool Option" dialog box.  If the component is a dynamic (primitive) model, then the appropriate model should be pulled up.  This does not yet support interactively moving properties between TinyCAD and Primcalc.
Things to beware using TinyCAD for Mason:
  • Mason in general is case sensitive. Be careful to use the proper case for parameter names and values.
  • The part's reference designator (L1, C1, TL1, Port1, etc.) must be unique to each device. Go to Special->Generate Symbol References to automatically handle this.  If you are using multiple sheets, remember to tick the check box for multiple sheets.  Forgetting to generate symbol references is a very common mistake.
  • Check out the warning on Smart Footprints.
TinyCAD in general has its own documentation. This guide mostly covers those aspects of TinyCAD specific to Mason.


 (Click for a larger view)




Using the "Show?" Feature

In TinyCAD, in the optimizer or statistical analysis block, if you set the "optimizer" or "argument" to not be shown ("Show?"), then that will disable that optimizer or goal.

If you set the Reference for ports or devices (Like _Port1, or TL1) to be not shown, that will remove the device from the circuit.  This will not affect Flags, Variable blocks (including microstrip and stripline properties), calculation blocks, or Frequency blocks.

If you set the argument for a variable block (including microstrip or stripline properties) or a calculation block to not be shown, that will remove that variable or calculation.

If you set the argument in the Flag block to be not shown, that flag setting will not be used.

The big exception is that devices (like TL1) can have arguments that are not shown, but are still used.

Power User Features that are potentially dangerous:

Mason can be used with TinyCad to simulate a design, output the microstrip lines and packages with a proper net list, even when that design includes non-simulation elements (see the schematic below, or download).

Instead of using the GND component in Mason, it is possible to use the built-in ground in TinyCAD (Power Tool Options, near the wire tool for drawing connections) if the Power Voltage is named "GND".  The only reason I put the ground port in Mason is to avoid having to type "GND" (one less thing to go wrong, as well).

Just as devices can have a "Package" or "File" parameter, devices can also have a "Nodes" parameter.  This allows a device to have more pins in the schematic than are defined in the simulation.  Consider the schematic below: the amplifier is defined to have a 5-pin SOT25 package.  The simulation wants the part to have two pins. The "Nodes" parameter maps the local ports of the device to the S-Parameter ports of the simulation.  In the example below, Local Port 2 is mapped to port 1 of the S-Parameters, and Local Port 4 is mapped to port 2 of the S-Parameters.  Ports 1, 3, and 5 are not used, and are therefore set to zero (do not confuse this with ground).  Therefore, the local ports 1 - 5 are mapped as: 0 1 0 2 0.  If one of the simulation ports is to be grounded or left open, the local port must still be mapped to one of the S-Parameter ports, and then in the schematic that port can be grounded or left open.


(click for a larger view)
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layout_test.dsn
(29k)
Gregory Kiesel,
Oct 4, 2010, 11:30 PM
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