ABSTRACT
This chapter analyzes the effect of radio-frequency interference (RFI) on the overtemperature detection referring to a thermal shutdown circuit. It presents the nominal operation of a common thermal shutdown circuit. The chapter shows the way the RFI superimposed onto a power transistor signals couples with the thermal shutdown circuit of a power device. It analyzes the effect of disturbances on the operation of this circuit. The chapter shows a solution to be used to increase the immunity to RFI of this circuit and presents the results of the experimental tests carried out on a test chip. In order to avoid permanent damaging of the system-on-chip due to an overtemperature condition, a thermal shutdown circuit is integrated on chip as close as to the heat source. The chapter points out the reliability of integrated overtemperature sensors employed in smart-power system-on-chip operating in harsh environment. It investigates the susceptibility of a thermal shutdown circuit to the RFI injected into the power device.
