Research On Modeling Of SiC MOSFET Based On ABM Device

Silicon carbide(SiC)metal oxide semiconductor field-effect transistor(MOSFET)operates at high temperature,high frequency and has low power loss,which makes it promising for a wide range of applications.The study of device modeling of SiC MOSFET has gradually become a hot topic for researchers,as accurate device models were the basis for circuit design and system development.Most of the current models do not consider the effect of temperature changes on the model parameters in real-time,which can lead to inaccurate simulation of the switching process in high temperature and frequency situations.To address this problem,the behavioral model of SiC MOSFET based on analog behavior modeling(ABM)device has been established in this paper.It is focused on the effect of temperature on the threshold voltage and on-state resistance,and solved the problem of inaccurate switching process of SiC MOSFETs under temperature change.In this paper,two approaches were used to model the behavior model of SiC MOSFET based on datasheet,which were based on the modeling tool Model Editor and ABM devices.The model based on the modeling tool Model Editor was only suitable for simulation under constant temperature,and the simulation of device behavior after temperature changes was not accurate.In order to improve the accuracy of the model in terms of temperature,a SiC MOSFET model based on ABM devices was proposed.A hierarchical modeling approach was used to divide the overall model into four parts,including channel current,internal resistance,inter-electrode capacitance and body diode,by means of layered modeling.section.1)Part of the channel current part.The problem that the threshold voltage does not change with temperature and insensitivity of the transconductance coefficient was solved by improving the Sah.C.T.equation by introducing a temperature regulation function for the threshold voltage and transconductance coefficient.2)Part of the internal resistance.The improvement was based on the principle of voltage-controlled resistance,the introduction of voltage and temperature parameters,and the influence of voltage on it compared with the traditional resistance model,making the on-resistance model of the combined control of voltage and temperature more accurate.3)Part of the inter-electrode capacitance.The improvement was based on the principle of voltage-controlled switched capacitor,and a function statement was used instead of switching devices of the traditional model to select capacitors.This reduced the number of switching elements and nodes in the model and solves the problem of simulation non-convergence due to more nodes.4)Part of the Body diode part.A separate diode model was established based on the modeling tool Model Editor,and the junction capacitance parameters were fitted with the output capacitance,avoiding the problem of repeated modeling of the drain-source capacitance.The SiC MOSFET model established in this paper based on the ABM device can realize the function of continuous temperature simulation.By introducing a temperature regulation,function to the threshold voltage,the problem that the threshold voltage of the SiC MOSFET does not change with temperature is solved.It makes more accurate for device switching simulation,which is important for the research of devices under temperature changes.Since ABM devices are discrete components,software with similar devices can also refer to this method to build models,which has certain reference significance for modeling.