Abstract
High-side gate drivers are substantially used in automotive industry because of the reduced power lost in the standby mode. They are used to drive a MOSFET or IGBT that is connected to the floating terminal and operate up to several hundred volts. High-side drivers are more complicated than low-side because it is more difficult to turn off a floating transistor. However, an important issue for high side gate drive IC is the capability of transferring low voltage logic signals to high voltage control voltage. This is normally achieved by a level shifter comprised of a set of LDMOSFET. The breakdown voltage of the LDMOSFET needs to be high enough in order to elevate the gate to several hundred volts. Meanwhile, the leakage current between LDMOSFETs has to be suppressed to avoid cross-talk problem. In this thesis, novel process architecture of level shifter is proposed and applied in 600V rated high voltage integrated circuit (HVIC). This design leaves out the N-epi layer or N-buried layer used in conventional level shifters. By T-CAD simulation and measurement, the newly designed device is proved to perform as well as conventional level shifters with lower cost and higher operation flexibility.