CMOS gate drivers with integrated optical interfaces for extremely fast power transistors

Novel power semiconductor devices such as GaN High Electron Mobility transistors and SiC MOSFET are allowing significant improvements on switching speeds. Currently, gate drivers are one of the main limitations preventing the highest switching speed operation of wide bandgap power transistors. More especially, isolation barriers are limiting the Common-Mode Transient Immunity (CMTI) of dedicated gate drivers. Here, we propose two CMOS gate drivers with integrated optical receivers to transfer both the gate signal and the gate driver supply directly by light. Two technologies are considered, namely bulk 0.18um CMOS and 0.18um SOI CMOS, both having ultra-low propagation delays and pulse width distortions. The proposed optical interconnect with optical fibers allows extreme CMTI values, defined by the packaging and the distance between light emitting devices and the CMOS gate drivers. These integrated CMOS gate drivers will offer the fastest switching speeds for wide bandgap power transistors.