Issue link: https://iconnect007.uberflip.com/i/1491842
44 DESIGN007 MAGAZINE I FEBRUARY 2023 Feature Interview by Andy Shaughnessy I-CONNECT007 As IC features continue to shrink, the PCB designer's job gets more interesting—signal speeds and rise times are increasing, they're encountering EMI and signal integrity issues once only seen in the RF world. Dr. Todd Hubing is a longtime EMC instruc- tor, president of LearnEMC, and a professor emeritus of the Electrical and Computer Engi- neering program at Clemson University. I asked Todd to discuss the challenges that shrinking silicon can present for traditional PCB design- ers, as well as the opportunities and benefits of smaller chip features. Andy Shaughnessy: Shrinking silicon is caus- ing an increase in EMI and SI issues for PCB designers and EEs. What sort of problems does shrinking silicon cause? Todd Hubing: When the features of an IC shrink, transition times tend to be faster, and the high-frequency content of digital signals tends to increase. When newer, faster ICs are used in products that were designed with the older versions of those ICs, those products can suddenly start failing to meet EMC or SI requirements even though there was no nomi- nal change in the design. ICs with smaller features can also be more susceptible to dam- age by voltage transients, though that largely depends on the mitigation features built into the design. Shrinking Silicon, EMI, and SI