Ground Bounce Noise Isolation with Power Plane Segmentation in System-in-Package (SiP)

Ground bounce noise (GBN) on DC power planes, due to a sudden change in the current drawn by an active component, can appear as an undesired fluctuation in the voltage between power and ground planes, which may lead to signal integrity (SI), excessive delays, false switching, and other electromagnetic interference (EMI) problems. With the operating frequency increasing and working voltages decreasing of the high-speed digital circuits in system in package (SiP), noise isolation has become a major concern for electromagnetic compatibility (EMC) design. This paper presents two novel structural designs using electromagnetic full wave simulation software HFSS for mitigating GBN and reducing EMI problems. Compared the straight gap with a perfect electric conductor (PEC) bridge, it is demonstrated that power plane isolation employs the pectinate structure can dramatically improve noise suppression in low-frequency. The structure of power islands with the low-period coplanar electromagnetic bandgap (LPC-EBG) cell is also modeled. Band-pass character is obviously shown in IS₂₁l curve for 2.85 GHz bandwidth in this case of -20dB, and notable noise suppression over 1.7 GHz compared a common power islands structure.