Issue link: https://iconnect007.uberflip.com/i/1540184
12 DESIGN007 MAGAZINE I OCTOBER 2025 with high coupling (red), can significantly impact the total noise coupling. Additionally, improved routing for the aggressor power rail can better channel the currents to the load, thereby reducing noise cou- pling from the aggressor to the victim power rails. Making these changes to the routing of both the victim and aggressor power rails reduced the total voltage ripple noise from more than 100 mV down to less than 10 mV. Gaining intuition through simulation, especially before hardware is built, can lead to low-cost PCB layout changes to mitigate EMI crosstalk and ground bounce. In this case, the resonance at 11 MHz on the aggressor power rail created a signif- icant noise issue on the victim power rail. Mitigat- ing the problem was easily accomplished by view- ing the E-fields in the EM simulator and adjusting the power rail PCB routing. Another topic for another day would be select- ing decoupling capacitors for flat impedance vs. fre- quency to help eliminate noisy resonances in the aggressor power rail. DESIGN007 References 1. A famous quote by signal and power integrity expert Dr. Bruce Archambeault, an IBM Fellow and IEEE EMC + SIPI 2025 general chair. 2. Founders of the signal integrity list server, si- list-bounce@freelist.org, also coined the term power integrity. 3. The Picotest S50 board, Signal Edge Solutions. 4. W3623B ADS Core, EM Design, Layout, HSD Ckt Sim, PIProk, Keysight Technologies. Heidi Barnes is a senior applications engineer at Keysight Technologies. She is a power integrity expert and instructor, and the 2017 DesignCon Engineer of the Year. F i g u re 5 : T h e o r i g i n a l d e s i g n , b e s et w i t h exc e s s i ve c ro s st a l k , i s m o d i f i e d to re d u c e t h e E M I c o u p l i n g . B ot h v i ct i m a n d t h e a g g re s s o r ro u t i n g a re m o d i f i e d to re d u c e ove r l a p i n t h e c u r re nt f l ow. T h e re s u l t i s a 1 0 X re d u ct i o n i n v i ct i m n o i s e r i p p l e. ▼ " " Mitigating the problem was easily accomplished by viewing the E-fields in the EM simulator and adjusting the power rail PCB routing.