Building Smart Things to Take on Tough Jobs

Smart “things,” whether connected to the Internet of Things (IoT) or relying purely on their local intelligence, are pervading almost every aspect of work and life. Today’s low-cost, low-power computing devices enable product designers to create new and more sophisticated features and capture and analyze data from processes and the environment.

As opportunities grow to deploy smart things anywhere and everywhere, some, inevitably, are destined for life in extremely harsh environments. These may be performing tasks such as accurate temperature monitoring inside an oven, “under the hood” automotive controls, in-boiler emissions monitoring, or managing down-hole drilling equipment at extremely high temperatures and atmospheric pressure.

People need assurances that these electronic systems will be reliable, even when exposed continuously to punishing environmental conditions. Moreover, they must not only survive but also must always perform to specification.

The CMOS technology that underlies ICs such as processors, memories and ASSPs is capable of withstanding temperatures up to 150°C. For economic reasons, ICs that are unlikely to experience such temperatures are usually not qualified up to such high temperatures. Instead, the performance is specified over industry-recognized commercial (0°C to 70°C) or industrial (-40°C to 85°C) temperature ranges. Other temperature ranges that may be quoted are extended ranges, which can be -40°C to 125°C and, of course, military (-55°C to 125°C).

One example of a smart device designed to be operated in harsh environments is the NXP Semiconductors SB0410AE complete motor-control System-on-Chip (SoC). It has a specified operating temperature range of -40°C to 125°C and is designed for industrial applications in harsh environments, such as laser-cutting or spot-welding equipment and forklifts and construction machinery. It integrates a quad valve and pump controller, four low-side regulated solenoid drivers, and a high-side pulse-width modulator (PWM) to drive a DC motor using external power MOSFETs.

The environment for an automotive controller can be extremely harsh, such as under the hood – where high engine temperatures combine with other environmental hazards such as oils – or in locations that are exposed to direct sunlight. For this market, qualification according to the stringent AEC-Q100 automotive quality standard is a dominant requirement. Infineon Technologies has qualified its TLF80511EJ LDO 5V-output linear voltage regulator to AEC standards, and the device is specified for operation over an extremely wide temperature range from -40°C to 150°C for use in instrument clusters as well as ECUs, and engines that employ the latest start-stop technology.

When designing electronic systems for use in extreme environments, engineers also need to be sure that associated components, such as inductors and decoupling capacitors, can withstand the worst-case conditions. Ceramic capacitors are known to lose capacitance at high temperatures, and derating is applied to ensure the minimum required capacitance at the maximum operating temperature. Also, new devices featuring very-high-temperature dielectrics are being introduced to address the growing demand for high-temperature electronics. On the other hand, Vishay’s TJ3-HT family of high-temperature toroidal inductors are developed specially for high-temperature applications and rated for temperatures up to 200°C.

Electronics for Extremely High Temperatures
As the relentless drive to achieve digital dominance over our world continues, the industry is looking for new technologies that are even better suited to harsh environments such as extremely high temperatures. Silicon-on-Insulator (SOI) technology has been shown to perform at temperatures over 200°C in niche applications such as space instruments. SOI technology also enables improved stability over temperature as well as lower static and dynamic power consumption.

The world’s major foundries are working towards introducing commercial Fully-Depleted Silicon-on-Insulator (FD-SOI) processes, and, indeed, NXP Semiconductors claimed to be first to market with an applications processor based on this technology, in March this year. By incorporating other design improvements, the device – a next-generation i.MX7 processor – achieves a 17-fold improvement in deep-sleep power consumption, as well as a 50% increase in power efficiency. FD-SOI devices also perform well at low supply voltages and can be manipulated to run faster when needed and consume less power at other times.

By extracting the best performance from existing technologies, while developing new devices that deliver better performance and withstand even harsher conditions, we continue to create solutions that help address the world’s challenges.