### OrCAD™ Design

I would like to share my views on one of many popular industrial EDA software: OrCAD. This electronic design automation tool is pretty much the standard and is in widespread use in the industry. It is not meant for the hobbyist, as it has a steep learning curve: OrCAD splits up every feature into standalone applications and each feature has its own program.

OrCAD Capture is one of the most widely used schematic design solutions in the world. Because it’s part of the OrCAD _PCB Design Platform_, it can be purchased as a stand-alone application yet will integrate seamlessly with other OrCAD applications as your needs expand or change. It comes with huge libraries of components; These large libraries are critical because creating new components can introduce errors that won’t be captured by any of the verification tools. That being said, regardless of the package you’ll eventually need to create some custom components yourself. OrCAD handles pin swapping much better than other software like Altium **™**. OrCAD has fast response times to common actions like copy, drag, popup properties etc. It also has very flexible DRC checking. In OrCAD I could mark a pin as NC and it transferred to layout as NC, never popping up as an DRC error for the branch called “unconnected pins”. In Altium, I had to explicitly put a script in query which would mark pins as NC in case I wanted to run NC rule against other pins.

The latest OrCAD Capture version has many new features. The design difference viewer performs logical and graphical comparisons between two designs, two schematic folders or two schematic pages and displays the differences in the form of a portable HTML format. The new advanced annotation feature lets users annotate multiple schematic pages at a time giving them complete control over their component annotation process in the design cycle. OrCAD Capture provides you with the capability to convert Capture designs to XML format and vice-versa based on the requirements. The new PDF export functionality lets users export Capture designs as a PDF file and provides intelligent design information.

OrCAD PCB UI is seriously fast. OrCAD PCB/Allegro has an amazing autorouter. It really works well and with proper placement it does a great job. However, it takes a long time to understand and configure. Basically, you have to configure things like libs, padstacks, etc. Allegro’s biggest weakness is that it does not have any real library management. Even the place parts option in the PCB has no way of displaying parts or symbols as they call them in logical folders.

Putting these things aside, the true power of OrCAD Allegro really shines when you want to do things like large complex boards or RF design. The shape editing tool in OrCAD/Allegro is amazing for copper pours and copper pour editing. Large copper pours don’t bog down the display either. In Allegro, Automatic length matching works very well. A lot of times it manages to make right length adjustments even in areas where one would think it is impossible. Its 3D rendering falls short, though.

As I had mentioned before, in OrCAD you have different applications for each feature. This is actually really inconvenient as you need to work with a few different windows opened while performing any function. While in Altium, the schematic editor and PCB editor can be accessed and worked on in adjacent tabs. Also, there is scope for alerting and updating changes in one window to other. The panels feature I mentioned in our previous Altium post also needs a special mention here, as it adds more convenience while working, providing easy access to SCH lists, PCB lists, etc.

Both Altium and OrCAD provide wizards to ease new PCB footprint creations. However, the wizard in Altium is more advanced and has more package designs compared to the one in OrCAD. Trying to create PCB footprints for components outside the wizard is similar in OrCAD and Altium just like any EDA software. Still, Altium feels more user friendly regarding shortcuts and number of clicks needed for any action, compared to OrCAD. Getting more into OrCAD might help me find it easier to work on in the future.

One major thing that separates OrCAD from the lower end CAD packages is the PSpice add-ons that allow full circuit simulation. It does have quite a learning curve but if you have it at your disposal, it can save you a ton of time and frustration on some of the more advanced mixed signal designs. There are even entire courses in college focused on just learning how to use this one feature. OrCAD CIS allows you to integrate component information in a database, something that is useful when working in a bigger team with an accelerated design cycle.

By: Tony Jose

References:
1. [http://www.orcad.com/products/orcad-pcb-designer/overview](http://www.orcad.com/products/orcad-pcb-designer/overview)
2. [http://www.orcad.com/products/orcad-pcb-designer/compare](http://www.orcad.com/products/orcad-pcb-designer/compare)