Analysis and Design of Current Recovery Circuit for PCB-Embedded Pick-Up Coil Current Sensor in GaN HEMT Power Semiconductor

Abstract

Gallium nitride (GaN) high-electron-mobility transistors (HEMTs) have been extensively utilized in various power conversion applications because of their high power density, rapid electron mobility, and superior performance in high-temperature environments. A printed circuit board (PCB) embedded pickup coil current sensor with a large bandwidth and high measurement accuracy is required for accurately sensing current variations caused by the high-speed switching of GaN HEMTs. This paper presents the analysis and design of a current restoration circuit for a PCB-embedded pick-up coil current sensor used for measuring GaN HEMT currents. The characteristics of the operational amplifier within the integrator of the current restoration circuit are examined, and an integral restoration circuit is presented to compensate for nonlinearity. In addition, the design methodology for the pickup-coil current sensor and proposed integral restoration circuit are provided. The results of various simulations and experiments validate the efficacy of the proposed analytical and design approaches, including that of the integral restoration circuit.