As consumers expect better performance out of their electronics, mitigating electromagnetic interference (EMI) becomes a bigger problem to solve

Apr 19, 2021
 

When we develop innovative techniques and technologies to mitigate electromagnetic interference (EMI) – including the first power-supply device with an integrated active EMI filter – our customers can lower system cost and meet EMI standards more easily without compromising power density, which enables smaller, more reliable, and more affordable electronics.

If you’ve ever noticed a flickering LED light in your house or strange noises coming from your radio, you might think these are paranormal events – but they could be examples of electromagnetic interference, said Cecelia Smith, who leads boost and multichannel/multiphase DC/DC products at our company.

But EMI is more than an annoyance or spooky behavior of your electronics: In the worst cases, EMI can cause electronic components to fail. As devices grow smaller and components get closer to one another, EMI becomes a bigger challenge for engineers to mitigate.

“Consumers want and expect better performance out of their electronics, which means EMI will continue to be a problem we need to solve,” Cecelia said. “Our company is developing techniques that reduce the amount of EMI generated to help make electronics smaller, more reliable and more affordable.”

Why EMI is a problem

Electronic circuits in close proximity have the potential to disturb one another through unintended EMI, which can degrade or even damage system components.

One of the worst offenders causing EMI is the switch-mode power supply, a ubiquitous circuit due to its efficient power conversion. These converters typically generate significant radiated and conducted EMI as a result of the high-speed switching of voltages and currents.

As shrinking electronics exacerbate EMI, and as switch-mode converters maintain their predominance, mitigating the EMI that they produce is a necessity for engineers designing these electronics. If not, EMI can cause significant setbacks late in the design phase that cost both time and money.

“We have seen the continued proliferation of semiconductors in our daily lives as electronics get smarter and more connected,” said Jeffrey Morroni, manager of Power, Isolation and Motors at Kilby Labs. “These more sophisticated and complex electronic systems are getting smaller and smaller with more components crowded together. These trends increase EMI, and the associated challenges are enough to keep engineers up at night.”

How to mitigate EMI

Our company’s engineers have been addressing the EMI problem for years, through a variety of innovative approaches.

The latest evolution is our company’s new 42-volt LM25149 DC/DC buck controller – the first power-supply device to integrate an active EMI filter, which senses the high-frequency noise and provides a low-impedance path for it, according to Ambreesh Tripathi, a systems manager at our company.

“It replaces the bulky, costly passive filter with a very small filter and, even better, the filtering is happening within the silicon itself," he said. “Using this device, design engineers can reduce the size of an external EMI filter by half.”

Jeff compares the active EMI filter to noise-canceling headphones.

“In noise-canceling headphones, there’s a sensor that measures the audible noise in the ambient environment and uses the speaker to cancel the noise in your ear so you don’t hear it,” he said. “Our solution works on a similar principle to cancel the EMI so there’s less noise. We’re helping solve this problem for our customers so they can focus elsewhere."

From ADAS to aerospace

Reducing EMI in the power supply is a growing challenge for design engineers as electronic content increases in advanced driver assistance systems, automotive infotainment and clusters, building automation, and aerospace and defense designs.
 

“The challenge is that we want more power in the same amount of space, and as the power density increases, so does the potential for EMI," Cecelia said. “For example, the car is changing and will look much different than it did 10-15 years ago. From the infotainment system to the camera system and higher-end lidar, automakers are exploring how these might evolve to a more fused architecture working seamlessly together."

Our company’s new power supply chips allow engineers to meet EMI standards without compromising their design’s power density, enabling them to achieve these smaller and more advanced systems. They are part of a large portfolio of TI’s power supply products that addresses various types of conducted and radiated EMI.

“We’ll continue helping solve EMI challenges in many different corners of the market – for common- and differential-mode emissions, across high- and low-voltage applications,” Jeff said. “This technology opens up customers’ eyes to realize we’re a great partner in helping solve problems they may not have thought we could or should be the ones to solve.”

Living our passion to create a better world

Helping our customers mitigate EMI is one example of how TI innovators are living our company’s passion to create a better world by making electronics more affordable through semiconductors. As each generation of innovation builds upon the last to make technology smaller, more efficient, more reliable and more affordable, new markets open and it becomes possible for semiconductors to go into electronics everywhere. At TI, we think of this as Engineering Progress. It’s what we do and have been doing for decades.