Computer Aided Design (CAD) refers to any software that aids developers in the creation of their product. ECAD (Electronic Computer Aided Design) and EDA (Electronic Design Automation) refer specifically to CAD software designed for electronics. In the electrical engineering field, CAD has become pivotal to the ongoing process of manufacturing complex electronics like printed circuit boards (PCBs) and microprocessors that are designed down to the subatomic level. The software provides a large number of tools and functionality that allow electronics companies to make the products that drive the age of information technology.
The Role of ECAD
Until an electronic device goes to the production line, ECAD is the most important tool of the design process. It performs the primary tasks of constructing electrical schematics, performing simulations, and creating physical blueprints for electronic devices ranging from the latest microprocessor to powerful graphic processing units. It is the primary reason that electronics have advanced from processors with just over 2000 transistors to ones with billions packed onto them.
The available functionality of ECAD software can be summed up as the design and testing of complex electronics schematics on both the physical and logical level. The schematics for both aspects are generated are stored in digital format with frequent backups, making it easier to modify and distribute.
On the electrical side, ECAD programs typically come with the ability to design the electronics schematics from the ground up and eventually run simulations to determine how the hardware will respond when an electronic input is given. This is done by using the software language to replicate the logical functions that electronics goes through. For a simple example, if an AND logic gate is shown on the schematic, the simulation would take all the inputs into the gate and perform the same process at the application level. The program would do this for all possible inputs in order to quickly and automatically test the schematic. Many of the programs also offer the ability to create “cells” that act similarly to logic gates or solid-state chips.
Every electrical component has a physical manifestation, and complete ECAD software manages this aspect as thoroughly as it cares for the logic process. The software allows the engineers to place the physical components represented in the electrical diagram onto a model of its physical form. Any discrepancies, such as overlapping parts or a lack of room, are noted and can then be corrected well before the manufacturing process.
There are a number of both open source and commercial options available for EDA software. On the commercial side, the top options include programs such as: Zuken’s CADSTAR, Mentor Graphics’ collection of programs, and Synopsis Design Compiler. The most popular open source tool is gEDA, developed for Linux due to the low availability of quality open source EDA tools.
The Future of ECAD
With the ongoing trends towards solid-state devices and placing more complicated systems on a single electronic component, the demand for powerful ECAD software will continue to rise. More open source options are appearing, meaning that both companies and scientists will have the tools they need to design electronics to control the giant robots and flying cars of the future.