A 10MHz 5-to-40V EMI-regulated GaN power driver with closed-loop adaptive Miller Plateau sensing

Abstract

To optimize the classic design trade-off between EMI noise and power efficiency in GaN power drivers at 10MHz and beyond, a closed-loop adaptive Miller Plateau sensing (AMPS) technique is proposed. In order to mitigate long delays and low accuracy issues in conventional Miller Plateau (MP) sensing approaches, an emulated MP tracking (EMPT) technique is adopted to achieve instant MP start point sensing. An isolated negative voltage sensor is designed for the EMPT to avoid considerable leakage current and enhance reliability without increasing circuit complexity. A noise-isolated feedback link ensures the closed-loop regulation accuracy by blocking the switching noise between HV and LV operation domains. Fabricated in a 0.35μm BCD process, the design achieves EMI reduction of 19.23dBμV in Band B (<30MHz) and over 9dBμV in Band C/D (>30MHz).