On-state and transient characterization of a monolithic MBS (MOS bidirectional switch)

This study deals with the perturbations that occur in a monolithic device: a MBS (MOS bidirectional switch) and its driver. A modeling of the parasitic coupling between the power part and the logic part is presented in the on-state. This leads to an analytical model that takes into account in its parameters the physical and geometrical specifications of the device. Therefore the parasitic gate voltage can be simulated with good results compared with experimental tests. This allows to assess that there is no substrate effect in the on-state. Perturbations are depicted in the transient state too. The use of the monolithic chip in a chopper (on inductive load) points out the fact that the substrate carries parasitic noise setting the isolation limits of a reversed biased PN junction. To conclude, the study of these phenomena allows to understand and to control the parasitic effects of the device that may happen in the on-state.