Martin Keenan (Technical Manager for Avnet Abacus) in Electropages (http://bit.ly/2h6Aby3) makes some good points about buying a ready-made radio module instead of designing a wireless block yourself. Though his comments are aimed at the Murata range of modules, the concept applies equally to others like ours here.
Freeing Up Design Resources
RF designs are notoriously difficult to get right. With a discrete design, specialist RF expertise is required for layout, signal routing, layer stack-up, interference and shielding, and this represents a big investment in design time.
Choosing an RF module, which is straightforward to integrate into designs thanks to the manufacturers’ directions, means designers don’t need to spend time on things like antenna or receiver placement. Ready-made RF modules essentially do all this work for you, so the development cycle can be drastically shortened.
With less time spent in development, the product gets to market quicker, beating the competition. And less time used on designing and optimizing a tricky RF sub-system means design teams can spend more time working on features that will differentiate the end product.
Performance Is Optimized
Using a module also provides reassurance that the RF system is fully optimized. Module manufacturers are experts in their field and you can be sure they have spent many, many design hours working on their modules to ensure the best possible performance from the smallest possible footprint.
In terms of performance, module makers continuously evaluate the latest RF chipsets to ensure their products are state of the art. A typical module maker offers modules with a variety of chipsets that might have slightly different features so there are plenty of options and if you have a particular chip manufacturer in mind that’s no problem.
To reduce footprint, module makers have access to specialist packaging technology that allows them to package IC bare die alongside passive components to incorporate a wireless chip, RF front end, complete power management system and chip antenna in a tiny area.
This technology is simply not available to the outside world, so the modules are more compact than a discrete solution could ever be. Modules that combine more than one communications protocol are widely available, such as WiFi and Bluetooth modules, saving even more space.
Fully Tested and Pre-Certified
While it is not always the case, most wireless modules on the market come with testing and certification to simplify RF compliance requirements. Discrete or chip-down solutions require extensive testing, which is extremely time-consuming. And anyone who has built their own Bluetooth system knows that it can take months to achieve all the necessary certification – weeks and weeks can be spent waiting for certification to come through and dealing with the associated red tape – and that’s if it passes. Having to redesign and reapply means it can take even longer.
Longer Life Cycles
Modules aren’t just for high turnaround consumer electronics devices. For product categories that have extended life cycles, such as healthcare equipment, wireless modules can actually help to extend the life of that product.
If a particular wireless IC goes obsolete, the module manufacturer can often replace it with another, newer part without changing the module’s footprint. This can help assure continuity of supply long beyond the demise of a particular chipset.
There are many areas in which wireless modules can reduce costs compared to discrete RF designs. As mentioned above, a much shorter design cycle and no need for specialist RF expertise can save on outsourcing costs. Specialist equipment, such as antenna matching and tuning equipment, is not needed, which can save thousands of dollars. And pre-certified modules also help save the costs associated with certifying an original design.
There are also production costs to consider. Since modules are tested by the manufacturer, they are effectively pre-yielded. Discrete designs will of course be subject to yield losses, as well as the costs associated with failure analysis and rework.
Operational costs can be cut, too. A module is a single SKU for procurement and inventory purposes. Managing an extensive BOM for a discrete RF sub-system is a lot more complex and costs a lot in admin time and money.