Analysis and Solution for RF Interference Caused by PMIC Noise in Mobile Platforms

摘要

Display modules have become inextricable components in recent mobile platforms; however, displays also represent the most common noise sources contributing to radio-frequency interference (RFI) issues. This paper considers RFI issues caused by power management integrated circuits (PMIC) that support display modules in practical mobile devices. The noise coupling from PMIC outputs to a mobile antenna is analyzed based on electromagnetic simulations and measurements. An alternative and practical method to evaluate the noise coupling is then suggested on the basis of transfer impedances of display power lines. Finally, a practical solution using selected multi-layer ceramic capacitors to improve the RFI issues is proposed and experimentally validated.