The Industrial Internet of Things (IIoT) is not a homogenous market and is challenging for typical semiconductor vendors who prefer to supply off-the-shelf standard components into the industrial space.
One-size does not fit all in IIoT applications - only customisation together with integration, yields the cost, power, size and optimisation needs that will enable the proliferation of the IIoT.
Designs are all about connectivity and it won’t be only a single part that is affected – manufacturing, logistics, the supply chain, energy supply and transportation are all expected to be transformed by the ability of the IIoT to streamline operational functions and create new levels of efficiency.
As well as connecting that data to the Cloud, the IIoT adds another layer of sensing, giving a more granular view of operations, enabling any variable that could affect production to be clearly viewed. Production and processes can be modelled more accurately, leading in time to the whole system operating autonomously.
The IIoT has provided a huge opportunity for OEMs to create new devices and services. Hardware companies are developing products that will be deployed to make the IIoT function. The connectivity with the Cloud gives OEMs the potential to move into service provision and offer remote diagnostics and management services, upgrades to software and many other Cloud services, adding further revenue streams.
For customers the IIoT offers the chance to streamline their businesses by reducing the amount of waste generated. It also enables them to optimise production and accurately view and model the whole process. Owners of plants are able to see their consumption of raw materials and other metrics in real time. They can also monitor the condition of equipment, allowing better planning of maintenance to keep the plant running optimally and reduce unplanned downtime.
Unprecedented demand
The extensive use of sensors has created an unprecedented demand for components. The intelligence of IIoT systems is both centralised in the Cloud and distributed widely in smaller intelligent devices.
These distributed devices are small, low-powered and normally contain sensors, actuators or both, depending on the application. They include devices such as smart valves, thermostats, flow sensors, cameras and level sensors. They also need networking capability.
Often situated in remote or hard-to-reach areas, battery power is used frequently, placing an emphasis on power consumption. To achieve the required specifications in all these areas usually requires custom silicon – which in many cases costs less than one would expect.
For a particular customer we work with, their first introduction to the IIoT was through smart valves for the oil and gas industry. These devices can be built using off-the-shelf components, but this often proves inefficient. They end up taking more space than necessary, are more expensive and are over-specified. These negatives can often be overlooked for less smart devices that rely on traditional computers for intelligence, but for IIoT applications the component count was much higher and the BOM costs expanded rapidly for the required ASSPs.
Custom silicon had the potential to cut those BOM costs, while optimising performance and cutting energy consumption.
The most advanced silicon process nodes, such as the Fin-Fet process nodes are typically only economical for the high-volume consumer segments or fundamental to achieve the speed and data-density needs of data-centre products. However, the smart edge devices that make up the IIoT segment can be well serviced by the more mature planar process nodes, that utilise heavily depreciated, and thus cheaper semiconductor fabs.
From almost two decades of focused development in these mature nodes to satisfy the mobile phone market explosion, these nodes are awash with extensive, silicon proven IP and integration expertise. That, together with a laser-like focus on cost and optimised low-power design, has led to a fantastic opportunity for the IIoT to exploit.
Historically, custom silicon has been considered as too expensive for small players, but the heavily depreciated fab and extensive IP libraries have opened up the possibility of custom ASICs for smaller customers. As well as reducing BOMs by up to 80%, custom ICs enable differentiation of products, which is essential in what is becoming a crowded market. Custom ICs offer greater security as they are harder to copy, and they also give the customer more control over the availability of the IC – which is important, as IIoT applications will usually have a longer lifespan than normal silicon.
Custom approach
The S3semi customer, detailed above, was a prime example of what is possible when using custom silicon. The industrial control manufacturer wanted to try a custom IC, but had no experience of the design and procurement process. It wished to increase its top-line revenue, by adding value to its existing products (such as enhanced connectivity), whilst also increasing its bottom-line through cutting the BOM costs.
The product chosen for the trial was a connected smart valve controller, which needed to be able to support multiple sensors for pressure, temperature and diagnostics. Current consumption needed to be less than 4mA. The controller was also required to support both Fieldbus and HART communication protocols. The customer also wanted to offer different product tiers.
If the device was built from off-the-shelf components, it would require a 16-bit microcontroller, Fieldbus modem and Flash memory, as well as discrete ADCs and other discrete analogue functional blocks that would include references, RTCs and DACs.
The design would have a high BOM cost, which would grow as the product tiering cost was accounted for.
Based on the desired functionality and future roadmap items provided by the customer, we gained an understanding of the customer’s needs, both for the present and the future. With those details, it was possible to create a custom silicon solution using its rich IP portfolio.
The design used TSMC’s mature 180nm process node and was based around a low-power ARM Cortex-M4 processor. The custom ASIC incorporated all of the fundamental building blocks of the system, including 14-bit ultra-low-power SAR ADCs, 12-bit DACs, power switches, analogue multiplexers, op-amps, sensors and power management.
For memory, the IC included Flash and SRAM, and for communications, a Fieldbus Medium Access Unit, and the HART interface were incorporated along with SPI, Parallel, UART and I2C interfaces.
Having all the main blocks integrated in the custom IC led to BOM savings of over 80%. Other benefits included meeting a strict power budget, a smaller form factor, higher levels of reliability and an improvement in signal integrity.
The silicon design is harder to copy than a discrete solution, so also offers a higher level of IP protection. These features differentiated the design from those of competitors and provided a solid base that the customer could build its different tiered products around.
| “One-size does not fit all in IIoT applications. Only customisation together with integration, will truly yield the cost, power size and optimsation needs to enable IIoT proliferation.” - Darren Hobbs |
Customising the IIoT
The IIoT offers a win/win situation for both the OEM and its customer. The OEM through its connected products can readily up-sell by adding new service capabilities, and today customers can see a real difference in their processes through the transparency and granularity that the IIoT offers, perhaps ultimately leading to a “pay as you use” model.
To take advantage of the IIoT requires a deep understanding of the benefits, and its, sometimes, confounding requirements. Goals such as low-power operation and low cost are hard to meet using-off-the shelf components, especially when the functions of the device include demanding tasks, such as precision sensing in noisy industrial environments.
But these demands can be readily met by leveraging from mature and cheap process nodes that are ideally matched to IIoT application spaces. The proven IP repositories for these nodes, integration expertise and system knowledge available through companies like S3semi, can offer an easier way to achieve results that can provide a significant BOM reduction, combined with size and power reductions, all in a single piece of silicon.
| Author details: Darren Hobbs is the Director of Marketing and Strategy at S3 Semiconductors |
