At first glance, a system-on-a-chip (SoC) might seem like the most cost-efficient option for your wireless design. However, the hidden design costs of using an SoC could mean that a wireless module is the better choice. In this Tech Talks session, product marketing manager, Joe Tillison, outlines the criteria for making the best choices for your design. Click here to watch the entire session and register now for future Tech Talks. Here are some of the key takeaways from Joe's presentation.

Start with a Break-Even Analysis

Today's highly integrated SoCs provide the lowest possible bill of materials (BoM) cost option. However, SoCs are more challenging to design with and thus require research and development (R&D) budget, specialized measurement equipment, and staff expertise in RF design and compliance testing. While modules are more expensive, they are easier to use and come pre-certified for RF compliance agencies, enabling faster time to market. So, how do you decide which option to use? Joe recommends starting with a break-even analysis.

The following break-even analysis table shows that, at lower volumes, the SoC profit is negative due to the upfront costs of using an SoC in your design.

The annual break-even volume between SoCs and modules in this example is around 300,000 units. Although the break-even point may seem surprisingly high, there is a simple reason: as chip pricing has come down, so has the gap between chip pricing and module pricing. At high volumes, there can be as little as $1 price difference between chips and modules.

SoC and Module Price Comparisons Ignore Other Hidden Costs

If you're only comparing chip pricing to module pricing, you're ignoring some hidden costs. Development with SoCs requires RF engineers with specialized skills, which adds to overhead development cost. Additionally, SoCs must undergo compliance testing and require the use of specialized lab equipment and facilities. Any issues discovered during compliance testing can be costly to fix in terms of redesign and lab expenses, all of which can cause time to market delays.

Wireless modules eliminate many of the risks associated with SoCs. They are easy to use in designs and involve only a few simple guidelines. Additionally, modules are fully tested and characterized by the vendor. End products using pre-certified modules inherit the module's certifications. Overall, modules provide a faster path to revenue.

Decision-Making Criteria

When choosing between an SoC or a module for your wireless design, consider the following important factors:

• Volume versus cost – what is your break-even point?
• Availability of resources – RF expertise, software and lab equipment
• Time to market costs – SoCs require longer development times
• Risk tolerance – lost time to market and market share if the project is delayed

Silicon Labs offers the best of both worlds. Our module and SoC families use the same tools and software, so the developer experience is the same no matter which option you choose. Our pre-certified modules, which have already been tested to meet alliance standards and RF regulatory requirements, ensure certification of your end products. Silicon Labs’ reference designs, technical documentation and support teams assist experienced RF engineers in efficiently designing with our SoCs and enable developers with little to no RF experience to add wireless connectivity to their IoT products using modules.

When it comes to adding wireless functionality to your products, there is no one-size-fits-all solution. Let us help you find the best choice for your wireless development needs. To learn more about our wireless module and SoC solutions, contact your Silicon Labs sales representative.