SMPS noise managing methodology for RFI solution in mobile platforms

In mobile platforms, RFI problems caused by the noises on switched-mode power supplies (SMPSs) have arisen. The SMPS noise which affects RF bands is generated by the voltage ringing at the switch transitions in the SMPS operation. This voltage ringing is caused by the parallel resonance between the chip-level capacitance and the PCB routing inductance in the off-chip level. In this paper, we propose a new SMPS noise managing methodology to reduce the SMPS noise in RF bands and optimize the PCB designs for SMPSs. Additionally, we consider the possible deleterious effect of the proposed managing methodology on the SMPS efficiency.