A different IC design philosophy driving forward IoT and IoE

Now we are set to go well beyond smart homes and smart TVs with the introduction of electronics into low cost everyday items. But why do we need everything to be connected? By incorporating an integrated circuit (IC) and tag with a unique ID into things, it is possible to assign time, location and context relevant data.

For example, manufacturers can record provenance of ingredients/parts, location and time of production, and supply chains can be tracked, which enable consumers to be assured of provenance and authenticity, to control counterfeit and grey market trade. The same technology could also be used to help reduce food waste, and even increase recycling with consumers able to access localised recycling information. And these are only a fraction of the potential use cases.

The IoE may seem like a utopian vision, but the technology has actually been around for a while. So far this has predominately been seen in low volume consumer engagement marketing campaigns or high value products. In the apparel market, Radio Frequency IDentification (RFID) ICs are used to improve fulfilment and reduce stock loss.

However, conventional silicon integrated circuits are not well suited for introducing intelligence and interactivity into the very low cost, high-volume fast-moving consumer goods we use daily. More widespread applications of this technology have been restricted mainly due to cost.

To reduce the price of silicon ICs, the industry has focused on decreasing the cost per function by moving to smaller and smaller technology nodes, packing transistors more densely, and offering more functionality per area with each transition. Increasing packing density is at the expense of complexity - more layers, more sophisticated manufacturing techniques and more design constraints.

This inevitably has led to increased design and verification costs, plus longer new product introduction cycles, promoting the design philosophy of complex processors, which then are programmed to perform a wide range of tasks. Professor Paul Kelly of Imperial College London called this a ‘Turing Tax’ (referring to Alan Turing’s ‘universal computing machine’), i.e. the cost of having an IC that is more complex than it would be if it had been designed specifically for a single use case.

Whilst this Turing Tax is low for applications where a processor is required to perform a large number of different tasks during its daily operations, e.g. in a PC or smartphone, the tax is high for the IoE market segment. For low cost everyday products, the key priorities are very low cost, flexibility and robustness. What we require is a new philosophy that enables us to design just enough computing for each of the tasks at-hand and no more.

As the silicon space is not aligned to this philosophy, PragmatIC had to rethink how to build low design and low unit cost integrated circuits. How could PragmatIC develop an environment where we could quickly iterate, without astronomical costs?

The final cost of an electronic system is made up of many aspects - basically it can be split into fixed and variable costs. The fixed costs are amortised from the capital required to build the fabrication, test and integration systems (CAPEX) and the operating overhead costs (OPEX) of those systems. The variable costs are made up of the design, simulation, test and verification hours of the IC itself, of its integration into the intermediate steps and the final package, and of course the material costs at the yields of the various steps. In the packaging world, this also includes the yields incurred incorporating the electronics into a high-speed industrial packaging line.

PragmatIC devised a new philosophy that brought benefits at all levels of this cost equation. The company’s FlexLogIC production system is a fully automated, fab-in-a-box which is capable of producing billions of flexible integrated circuits (known as FlexICs) per year. With a compact footprint and CAPEX 100x lower than traditional fabs, and production time of less than a day, this enables the rapid time to market of multiple designs.

The FlexICs are built on a flexible, robust substrate. They are ultra-low cost, thinner than a human hair, and can be integrated into everyday objects. The IC design tools used are standard industry tool sets and will be familiar to anyone with experience in more traditional design environments. The combination of lower upfront IC design and production costs, with short development times, give designers the freedom to explore new ideas and see the results quickly. This has led to some interesting applications of the technology and we expect to see an increasingly diverse range of use cases driving forward the Internet of Things towards the Internet of Everything (IoE).