Digital active gate drive of SiC MOSFETs for controlling switching behavior—Preparation toward universal digitization of power switching

Abstract

In this paper, a digital active gate driver for SiC power MOSFETs is proposed.High-frequency switching with SiC power MOSFETs can realize an integrated power circuit with higher power density. However, the large surge voltage and ringing caused by the fast switching will lose the reliability of the device and increase electromagnetic interference (EMI) problems. To achieve highfrequency switching without these drawbacks, an active gate driver based on the architecture of a digital-to-analog converter has been designed. The gatesource voltage waveform of the MOSFET is generated directly and flexibly by a multibit gate signal sequence, considering the device characteristics and a variety of circuit conditions. Effective gate signal sequences are investigated by focusing on the switching trajectory on the state space of the device, which is discretely controlled through successive transitions between operating points. Experimental and simulated results confirm that the proposed gate driver effectively suppresses and regulates the surge voltage and ringing during turn-off.

Digital-Twin-Compatible Optimization of Switching Characteristics for SiC MOSFETs Using Genetic Algorithm

“…The fundamental idea of AGD is to control the slew rate of the power device actively during the switching transient to suppress unwanted overshoots in device voltage/current and resulting EMI, while achieving a fast switching. This can be done either by actively changing the gate resistance [4,5,7,8], applying a variable gate-source voltage (V GS ) [6,[9][10][11][12][13][14], or limiting/boosting the gate current [15][16][17]. Initially proposed to drive Si IGBTs [11,15], AGD has been intensely studied for SiC MOSFETs in recent years, with typically nano-second order control due to the increased switching speed.…”

Slew rate control of switching transient for SiC MOSFET in boost converter using digital active gate driver

“…Several reports have been on a digital active gate driver for power conversion circuits. The methods are divided into three categories such as gate resistor selection [15][16][17], input gate current control [18][19][20], and input gate voltage control [21,22]. Reference [15] developed a programmable active gate driver for the GaN HEMT bridge by actively selecting the output gate resistance, suppressing the EMI noise without increasing the switching loss.…”

“…The aim of this paper is to verify the practical use of the digital active gate driver to power electronics systems. This paper applies the digital active gate driver [22] to a practical power conversion circuit with SiC MOSFETs. The switching surge voltage and the efficiency are experimentally suppressed using the driver with the slew rate control of the power semiconductor device.…”

“…The drivers for SiC power devices require both a large current supply and high‐speed capabilities. We have proposed a gate‐voltage‐controlled digital active gate driver for SiC MOSFETs using a high‐speed gate drive circuit with GaN HEMTs [22]. The proposed gate driver, which is based on the architecture of a digital‐to‐analogue converter (DAC), shapes the gate driving voltage waveform by a binary gate control signal.…”

“…The proposed gate driver, which is based on the architecture of a digital‐to‐analogue converter (DAC), shapes the gate driving voltage waveform by a binary gate control signal. Its concept was investigated with resistive load using the prototype digital active gate driver in [22]. The potential of the driver was also verified for the high voltage circuit with SiC MOSFETs with an inductive load [23].…”