Integrated Photoreceiver For An Isolated Control Signal Transfert In Favour Of Power Transistors

The galvanic insulation around power transistors is often a requirement: the reference point of the power transistor may be at a high voltage level (series connected transistors or high voltage full bridges or inverters) and the insulation between the gate driver (operating at this reference point) and the external control part is fastidious. The optical insulation is a good candidate for high insulation levels, but this solution is costly while relaying on discrete implementations. In this paper, it is demonstrated how we have monolithically integrated a photoreceiver within a 600 V intelligent power device: first, a model has been developed (concerning the static and dynamical behaviors). Second, the model has been validated by a comparison with finite elements simulations (it has been used to forecast possible interactions with the main power part). Third, a 600 V power MOSFET with an integrated photoreceiver has been designed and manufactured, without any modification of the power transistor´s process. Simulations and modeling have been used to study and to analyze the interactions between the power device and the photoreciever integrated within its active region. Our prototypes have been checked out in practice. Added to an intelligent switch, this solution simplifies the implementation of power devices while reducing costs.