Choosing Electronics Components

This is perhaps the most tedious step in the design process, but is crucial to a successful design. Choosing the right part for your design could be the difference between finishing your project and giving up in frustration.

All integrated circuit manufacturers work hard to make their designs robust and perform their function at the lowest price they can, but not all companies are equal. This is especially true when it comes to making their parts easy to use.

Since there are hundreds of thousands (millions?) of different components on the market, it isn’t possible for me to give a complete rundown, but what I can do is provide some general guidance on how to select the best component for your purpose.

When it comes to actually finding parts, I like to use the search capabilities provided by my favorite vendors, this way I know the product will be available and I can choose components based on the actual cost to me and available inventory.

Another way to search for parts would be to go to a particular company’s website and browse their parts catalog for a solution. For example, if I know I need an ADC for a project, I may start with a company that is well-known for their ADC products such as TI. This has the advantage of often leading to a highly usable solution.

My four personal favorite avenues for finding parts are:

  1. - Mouser is a popular worldwide component distributor that has a wide range of products. Their selection is (in my experience) not quite as large as Digi-Key’s, but I prefer their website design, the better filtering system, and the more logical component organization.

  2. - Digi-Key is another popular worldwide component distributor. They probably have the largest component selection of any distributor, have great customer service, and are fast to ship. Overall I would put Mouser and Digi-Key about even, and certainly at the top of the list.

  3. - This is a relatively new service that is like Google for electronics. Octopart searches through many different distributor channels for the part you want. There are many things I like about this service. They always put the datasheet in an easy to find spot, they provide a useful product summary, and show you price comparisons from different distributors. But there are drawbacks, Octopart still seems a bit unrefined and I don’t think it is worthwhile to compare prices from different distributors unless you are only buying a single part or are buying a massive quantity of components and shipping costs are negligible. In a few years Octopart may become the standard for finding your parts, but for now it still has some room to grow.

  4. - They have a database of over 70 million electronic components, each with a PDF datasheet and is working on scaling the site up to 350 million parts (up to about 180 million in November 2013). In addition to datasheets they also provide inventory and pricing information from some of the major suppliers. This is a great resource.

2016 Michael here, I love Octopart, use that.