Ferrite layer and high dielectric constant BaTiO3 for power integrity

In mixed-signal systems, effective noise isolation between analog and digital circuits is required for power integrity (PI). In this paper, Ferrite absorb material layer is deposited under the power plane to absorb high frequency noise from 500 MHz to 10 GHz. High dielectric constant nano BaTiO₃ is used between the power plane and the ground for large buried capacitance to filter high frequency noise. First, noise isolation for High Dielectric Constant BaTiO₃ Substrate is researched. Then, noise isolation for Ferrite Absorb Material researched. Third, the above two noise isolation are combined to form the designed technique. The designed power / ground structure from top to bottom is Power plane / Ferrite / nano BaTiO₃ / Ground. The noise isolation is greatly improved for the designed power / ground structure than that for FR4 substrate without ferrite absorb material layer. In the mean time, the signal integrity effect is simulated, and the designed power / ground structure causes no signal integrity problem.