Letteratura scientifica selezionata sul tema "High dI/dt"

Abstract High di/dt 4H-silicon carbide (SiC) gate turn-off thyristors (GTOs) are investigated and developed for fast switching-on application. This work has focused on accelerating the turn-on process to improve the di/dt characteristic, and the n-base dopant concentration is carefully designed to increase the injection efficiency of top P+N junction. With reducing n-base dopant concentration from 2.3 × 1017cm−3 to 6.8 × 1016cm−3, the injection efficiency is increased about 18%, and consequently the current rise-up process and subsequent lateral propagation of the anode current are obviously accelerated. Experimental results show that the di/dt capability is greatly improved and a high di/dt of 126 kA cm−2 μs−1 is obtained. The excellent di/dt performance makes the designed 4H-SiC GTO a promising candidate for fast switching-on application.

An enhancement-mode gallium-nitride high-electron-mobility transistor (E-mode GaN HEMT) operated at high frequency is highly prone to current spikes (di/dt) and voltage spikes (dv/dt) in the parasitic inductor of its circuit, resulting in damage to the power switch. To highlight the phenomena of di/dt and dv/dt, this study connected the drain, source, and gate terminals in series with inductors (LD, LS, and LG, respectively). The objective was to explore the effects of di/dt and dv/dt phenomena and operating frequency (fS) on drain-to-source voltage (Vds), drain-to-source current (Ids), and gate-to-source voltage (Vgs). The experimental method comprised two projects: (1) establishment of a measurement system to assess the change of electrical characteristics of the E-mode GaN HEMT and (2) change of the fS and the inductances (i.e., LD, LS, and LG) in the circuit to measure the changes in Vds, Ids, and Vgs, thus summarizing the experimental results. According to the experimental results on electrical characteristics, a gate driver circuit may be designed to drive and protect the E-mode GaN HEMT while being actually applied to a 120-W synchronous buck converter with an output voltage of 12 V and an output current of 10 A.