Power Distribution Network Impedance Analysis considering Thermal Distribution

Abstract

In this paper, we analyzed a power distribution network (PDN) impedance considering thermal distribution. Due to the development of integrated circuits (ICs) towards high density and high performance, the supply voltage has been reduced while power density has been increased. Shrunk supply voltage causes a low voltage margin and high temperature caused by the high power density varies the circuit parameters of the PDN. Thus, considering the operating temperature effects for a robust PDN design is essential. However, the previous power integrity analysis is not focused on temperature effects on PDN. Hence, impedance analysis of PDN considering thermal distribution is essential. Therefore, this research analyzed thermal distribution effects on the self-impedance of PDN. By using a W-element model, we analyzed thermal distribution effects on PDN self-impedance by circuit simulation. As a result, the difference in self-impedances is observed between the PDNs with other thermal distributions in spite of current loop path and mean temperature; The capacitance has same value as the capacitance considering mean temperature of thermal distribution; The value of the resistance closes to the resistance considering the temperature at the probing point, not the mean temperature.