Immunity analysis of an LDO using identification of operating region transitions

Distortion Contribution Analysis for Identifying EM Immunity Failures

“…These signals serve as input to the model. A preselection can be carried out [7], [8] to include only those devices in the analysis that see a significant part of the interferer at their input ports. 2.…”

“…To limit the number of simulations, we can include only those devices and interference frequencies for which the interference level at the input ports is significant. In [7], [8], devices are preselected based on the occurrence of operating region transitions. The AC simulation used for finding the feedback impedances also serves for determining all node voltages in the surrounding linear part of the circuit as soon as i DS is known.…”

“…The method can be used together with a preselection step, like in [7], [8]. Using this step, only those devices are selected that show strongly nonlinear behavior.…”

“…In [7]- [9], individual devices are pinpointed that are potential contributors to immunity failures. However, the method in [7], [8] does not result in a quantified prediction of distortion components and the method in [9] still requires carrying out many DC analyses of the full circuit and focuses only on DC shifts. There remains a need for a proper distortion contribution analysis (DCA) for immunity verification.…”