Whether it’s preventing systematic failures or anticipating and mitigating future risk, functional safety has changed the way engineers think about designing systems

Aug 24, 2021
 

Why did your smartphone crash in the middle of that important phone call? It might have been an aging or overheated component. Or maybe you unknowingly damaged a critical component in the phone’s processor when you dropped it recently, which caused the entire system to randomly restart.

When that processor is in your smartphone, the worst result is a few moments of frustration. If it had been in your vehicle’s adaptive cruise control system, then the consequences could have been much more serious.

"All electronic components will fail at some point in time – that’s just a fact of life," said Bharat Rajaram, whose job as director of functional safety at our company is to anticipate all the ways this might happen with our components. "And these days we see a greater prevalence of electrical components performing critical functions – from fluid level monitoring in chemical plants to autonomous vehicle navigation and aircraft lift control."

Since there’s not much an electrical engineer can do to stop time from passing, how do we help equip system designers who are using our components ensure random events don’t put lives in danger? And, given that there are so many things that can go wrong with an electronic component, why don’t the systems around us fail more often?

Preparing for all eventualities

The answer, says Miro Adzan, general manager for advanced driver assistance systems at our company, is functional safety.

“You can’t prevent random faults from happening, so functional safety involves building monitoring and mitigating safety mechanisms into a system to address them," Miro said. “A functional safety mechanism might involve constantly monitoring the braking signal in your car to check that it doesn’t deviate from the expected range. If it does deviate, the safety mechanism can flag that something might be going wrong and needs to be checked."

Functional safety concerns also appear throughout the home and workplace. If you’ve ever noticed your phone turning off because you left it in the sun, then you’ve benefitted from a functional safety mechanism that might have prevented a potential battery fire. Or, if you’ve ever worked near a robotic arm without a physical safety barrier, then you might thank the invisible work of radar sensors set up to help prevent it from swinging into you.

To anticipate these potential hazards, a system’s electrical design engineer must understand all the possible causes of these dangerous failures at the circuit level, their likelihood of occurrence, and how to reduce risk to acceptable level by implementing integrated circuits (ICs) that support functional safety. For the simpler ICs among our Functional Safety-Capable products, such as low dropout (LDO) regulators and thermistors, we equip engineers with information to incorporate them into functionally safe systems and to analyze the design. For more complex components among our Functional Safety Quality-Managed and Functional Safety-Compliant products that incorporate a range of safety mechanisms into the IC itself, we specify their diagnostic coverage in a failure modes effects and diagnostics analysis (FMEDA).

For example, our multi-channel power management ICs monitor voltage rails for deviations. You might find these in any type of electronic system, from controlling a human-robot collaboration system in your workplace to managing the battery of your electric car.

Preventing systematic failures

Preparing for random events is only half the battle in ensuring a product meets functional safety requirements, however. The other source of risk is systematic failures in the development process itself.

During the development process, all our products undergo a rigorous company-wide, quality-managed development workflow. Furthermore, our most complex Functional Safety-Compliant devices incorporate specific systematic capability compliance recommendations based on the functional safety standard developed by the International Electrotechnical Commission (IEC 61508) and the automotive-specific functional safety standard of the International Organization for Standardization (ISO 26262), both developed with our support.

Additionally, our functional safety development process has been independently certified by the technical inspection agency Technischer Überwachungsverein (TÜV) SÜD to further demonstrate that all the recommendations have been met.

All of which means that if on your way home from work you turn on an automatic cruise control that uses one of our Jacinto™ processors, you can rest assured that the system of sensors, software, actuators on the processor and all of its safety features have been independently assessed and verified.

Anticipating future risk

These standards have changed the way the industry thinks about designing existing systems – such as taillights and infotainment systems – in a functionally safe manner. But that doesn’t mean the job is done.

“People now appreciate the importance of functional safety," said Bharat, who is currently working with the IEC to revise its general functional safety standard. "But as we continue to proliferate the deployment of electronic and programmable systems to various critical applications, we need to help continuously update these standards as the state of the art continues to change."