A nMOS-R Cross-Coupled Level Shifter With High dV/dt Noise Immunity for 600-V High-Voltage Gate Driver IC

In digital integrated circuits with multiple power domains, level shifters (LSs) are essential circuit elements that can transform the voltage region from low to high. However, high-frequency gate drivers can generate hundreds of voltages per nanosecond noise (high dV/dt noise). Such high dV/dt noise can cause malfunction of a conventional pulse-triggered cross-coupled LS (CCLS) that is used to control the high-side nMOS switch. In this article, a novel LS with noise immunity is proposed and investigated. Compared with the conventional resistor load LS, the proposed circuit adopts nMOS-R cross-coupled (NRCC) LS, and realizes the selective filtering ability by exploiting the path that filters out the noise introduced by the dV/dt. The high-voltage gate drive integrated circuit (HVIC) is implemented using a 600 V silicon-on-insulator (SOI) BCD process. Analyses and experiments show that the proposed design can help the HVIC maintain a high common-mode transient immunity (CMTI) of up to 137 V/ns while allowing a negative VS swing down to -9.4 V under a 15 V supply voltage. Compared with the traditional HVIC with resistance load LS, the proposed novel HVIC with the NRCC LS improves the noise immunity of dV/dt by 182%.