Almost every electronic product that we find on the market consists of one or more electronic circuits. These circuits work independently or collaboratively within that product to complete a shared goal. The idea behind circuit designing is to solve an electronic problem using basic analog or digital circuits. You can use electronic components such as diodes, resistors, transistors, and capacitors for analog circuits. When the design problem includes calculations, you can use digital components such as logic gates or microcontrollers for digital circuits.
In this tutorial, we will discuss the concept of circuit design. We will overview some of the software programs for making schematics, wiring diagrams, and PCB layouts.
Electronic Design Automation
Electronic Design Automation, or Electronic Computer-Aided Design, is one of the major steps in a typical electronic product development cycle. At this stage, engineers use different software tools for designing electronic circuits and systems from the ground up. Typical workflows in an EDA environment include:
- Analysis and verification
- Manufacturing preparation
The basics of an EDA/ECAD tool is to create electronic schematics and layouts of an electronic system. With that requirement, we find that all EDA/ECAD tools come with a Graphical User Interface. This interface makes it easy to draw 2D/3D schematic diagrams. Users select components from a standard library and place them for a schematic generation. Here, the component is placed in the schematic layout connected to other components with nets or wires.
Although this is not a requirement for some EDA/ECAD systems, simulation plays a major role in modern engineering design. By definition, simulation is a process where we try to imitate real-world processes over time. In the context of ECAD systems, we simulate circuits to study the behavior of electronic components over time. Most importantly, simulation comes in handy when we want to analyze the signals at different points in our circuit. Most EDA/ECAD simulation tools for schematics use PSpice. This is a circuit analysis tool that allows for signal analysis at different points in a circuit. However, PSpice requires your components to have a SPICE model library.
Analysis and Verification
EDA/ECAD’s circuit analysis and verification is a powerful, inbuilt tool for checking whether the given electronic system meets the specifications. Specifications govern the models’ operational limits. Therefore, any designer must prove that their designs work as required.
If you are working with a modern EDA/ECAD tool, you are likely to perform all the steps of the engineering design workflow under one roof. This means that you no longer need to export your designs to a third-party tool for manufacturing preparation. All you have to do is create the manufacturing documents within that same program since EDA/ECAD tools now carry more advanced design features.
Comparison of Popular EDA/ECAD Programs
Have you ever noticed that most online tutorial schematics have a Fritzing logo ? This is because Fritzing is a very popular toolkit with hobby electronics and DIY engineers. It is popular because it is a simple, yet powerful open-source tool for anyone to build professionally looking breadboard layouts. Most importantly, it allows designers to build schematics, create PCBs, and generate PCB fabrication files. Personally, I really like Fritzing because there is a large collection of libraries for parts. But if you fail to find the library for your part, you can always build your own; it’s simple.
The main feature of Fritzing is that it has three main views where you can choose from: Breadboard view, Schematic view of PCB view, but the version that I am using has an extra Code view. I usually like to work in the breadboard view because I will virtually create the breadboard version of my project. So, this means that there is no longer any need for a physical breadboard to build the circuit. This is also a great tool for exporting diagrams.
Building a circuit in Fritzing is straightforward; you drag and drop the components from the parts palette window. Next, arrange the components to your liking and then connect all parts to complete the circuit. If you notice, any change that you make in the breadboard view will also reflect in your schematic view and PCB view. The schematic view shows a schematic representation of the project, while the PCB view shows the PCB representation of our project. Finally, you can also write your Arduino code in the code view and upload it to your board. Writing the code, selecting your board, or setting the serial ports is the same as the conventional Arduino IDE.
If you are looking for an easy-to-use EDA/ECAD software tool suite that can handle complex design tasks, then Eagle is the package for you. Professional engineers rely on Eagle because it is flexible and it provides high-end functions.
What I like about Eagle is its simple multi-window user interface. Navigation is also simple, and you can easily customize the design parameters.
Like any other EDA/ECAD package, Eagle comes standard with schematic capture, board layout, and autorouter, all in a single GUI. But what sets Eagle’s schematic capture apart from the competition is that you can develop hierarchical designs. This allows you to look at your project from a system-level view.
For example, in designing a sensor project, a hierarchical top-level schematic might have modules such as a microcontroller, power, signal conditioning, and output. These individual modules have their own set of sheets which you can double click and edit. Furthermore, Eagle allows you to design and simulate your schematics using LTspice. This enables you to predict the behavior of your circuit.
Without a doubt, one of the big names in the EDA/ECAD industry is Altium. This company provides electronics design software for high-end industries such as automobiles and airplanes. Although they have different product offerings in their portfolio, Altium’s flagship product has been Altium Designer.
This industry-leading EDA software combines all the tools you need for product design in one package. Of course, reviewing Altium Designer is beyond the scope of today’s article. However, I want to discuss the free version of their product, CircuitMaker, which runs on Altium Designer technology.
Unlike Altium Designer, CircuitMaker is targeted at the hobby or maker community. Therefore, users like you have access to an EDA package that inherits features from a great tool. Such features include:
- Multi-tab design editor
- Hierarchical schematic entry
- Native 3D capabilities
- User configuration parameters
- Team project management
- Concurrency editing
You also have access to a powerful engine and extensive component library. With CircuitMaker, you can quickly draw, edit and combine layouts. Its beauty is that you can easily share and collaborate your designs online.
Another EDA package that packs a punch is KiCad. Some users call it one of the best open-source hardware development tools.
Just like any other EDA/ECAD package, KiCad handles schematic capture and PCB layout. For manufacturing documents, KiCad can generate Gerber files for you.
A major selling point of this tool is the high level of abstraction. The developers of KiCad have gone to great lengths to hide the complexity of advanced design features so that new and inexperienced developers get up to speed quickly. Also, professional users find KiCad’s new features attractive.
Generally, if you are looking for a good cross-platform electronics design toolkit, KiCad might be the one for you. Another important aspect is that if you are a fan of circuit simulation, KiCad will work for you. The recent versions of KiCad come pre-loaded with ngspice.
Ngspice is a mixed-level electronic simulation tool. The program offers many models for active, passive, analog, and digital components. For presentation purposes, KiCad helps you by creating 3D views of your project.
EasyEDA takes a different approach to software distribution. They offer a fully web-based schematic and PCB design tool. This trend in software licensing models has been increasing over the past few years due to the several advantages of cloud-based systems.
EasyEDA leverage this model to provide a free and easy-to-use EDA/ECAD that runs in your web browser, irrespective of your operating system. I really like this platform because you can find a large collection of open source projects that will help you speed up your designs. This is particularly important if you are working on a tight budget or deadlines. Also, EasyEDA can create private or public projects; this determines who on that platform can view your designs. Just like any desktop EDA/ECAD tool, you can perform spice circuit simulations in EasyEDA.
Again, Electronic Circuit Design is the methodical selection of electronic components that work to achieve a set of design requirements when connected. You need a set of tools to develop your circuits, and there is a wide selection for you to choose from. Here is a table that summarizes the features of some of the most popular EDA/ECAD tools available to hobby designers.
|Fritzing||Interaction Design Lab|
|limitations in miniaturization and |
replication of prototypes
|Eagle||Cadsoft/ Autodesk||Schematic capture|
|Schematic and PCB limitations |
in the free version
|Integrated Spice simulation|
|No limits on layers, size of PCB, number |
|Mixed analog/digital simulation|
|KiCad||KiCad Developers||Schematic capture|
|No limitations on the purpose |
of your use
|Supports simple schematic|