Capturing Electronic Design

Stop inventing the same thing over and over again… 

We’ve all been there. Creating the same thing repeatedly. We know it, we recognize it. When you think about it, it’s obvious. Why shouldn’t one create a building block that can be used again and again? Since the building block already have been used in previous designs, it has been certified to a certain level already and that will reduce time to market significantly.  

Before creating your new electronic schematic, you must enter a certain mindset. Your new schematic must be as generic as possible. Think of it as a green box where signals enter the box and exits the box. One should not have to examine what’s inside the box, purely trust it! 

When designing a reusable building block, it should be made in way that any electronic designer can interpret it and use it. The following points should be considered, 

• Power Supply requirements (Voltage, Ripple, and power consumption) 

 In the schematic you should put this as text in a box letting the user know what to expect and to consider. 

• Net names 

Always use net names that reflects the function of the signal, like in the example below. I2C is the bus and it contain two signals which is clock and data. 

• Pull-up and Pull-down resistors

• Exiting with individual signals or with a bunch of signals in a so-called Harness/Bus.  

In this example there’s only one I2C bus exiting in a so-called harness. Harnesses in Altium can be identified by its thicker harness wire and it’s often used color which is blue.  

• Adding specific PCB Layout design rules in the schematic block 

In this case there a specific PCB layout rule that control the width of the VDD net to U3. This requirement will be transferred to the PCB layout. 

• Keeping the components unannotated 

Different projects have different requirements for naming the components. When they are unannotated it’s up to the user later to determine the annotation.  

Since all the signals and the power exit through ports in the green box you need to put some effort into naming these. They should be self-explanatory. Always imagine that you should be able to use a block like this without asking any questions. As you can see in the picture below there’s a recycle symbol inside the box. This symbol indicates that it’s a reusable building block.  

Once you have selected your components and the design is in place you need to store your building blocks somewhere. The best way of storing it is in a version-controlled environment where you will have the option to trace all the changes back and forth. There will be times when you need to update your building blocks due to enhanced functionality or obsolete components. When using them later, make sure you are using the latest one.  

If your CAD tool allow you to store it in a more integrated way, that’s even better.  

At Zellaco we use one of the largest tools providers globally for our printed circuit boards (PCB), Altium. This solution makes it easy for us to implement design reuse and to share our designs with our clients. Would you like to know more about our development processes and how we take on a project? Don’t hesitate to contact us.