method for establishing a nonlinear segmented time sequence model of high-frequency dynamic loss of a GaN HEMT device

Abstract

The invention discloses a method for establishing a nonlinear segmented time sequence model of high-frequency dynamic loss applicable to a GaN HEMT device. According to the electrical parameter statesof different time periods in the switching process of the device, the loss is specifically calculated in the four stages of switching-on, switching-off, switching-on conversion and switching-off conversion. In the modeling process, the problem that the dynamic impedance is increased under the specific high-frequency work of the device is considered, and accurate extraction of parameters influencing the change of the dynamic conduction impedance during the high-frequency work of the device is realized by building a circuit; In the modeling process, the gate charge is adopted to replace a device output capacitor to directly calculate the loss, and complex and inaccurate calculation caused by the change of the capacitance value along with the voltage is avoided. Besides, the external capacitor is connected in parallel between the drain electrode and the source electrode outside the device for the first time to compare the difference between the drain electrode current and the actual channel current of the device, and the specific source generated by the difference and the real influence on the switching loss are analyzed, so that the correction of the loss calculation of the model isrealized.

Description

technical field [0001] The invention relates to a nonlinear segmented timing measurement method for high-frequency dynamic loss of a GaN HEMT device. Background technique [0002] AlGaN / GaN HEMT devices are a new generation of wide-bandgap semiconductor devices after silicon-based and silicon carbide-based MOSFETs. They have incomparably superior performance of silicon-based and lower cost than silicon carbide-based. Due to the characteristics of AlGaN and GaN materials such as wide bandgap, polarization effect and conduction band discontinuity, the prepared AlGaN / GaN HEMT devices have high frequency, high withstand voltage, high current, high temperature resistance, and strong anti-interference Field effect transistors with superior electrical properties. In particular, the interlayer materials of HEMT devices have a band gap and a high dielectric constant, so that the junction capacitance can be controlled to a very low level. The input capacitance (Ciss), output capacita...

AI Technical Summary

Problems solved by technology

[0010] However, in terms of high-frequency dynamic characteristics, GaN HEMT devices have unique electrical characteristics compared with traditional Si / SiC power electronic devices, mainly reflected in: GaN HEMT devices do not have reverse recovery characteristics; their parasitic capacitance and The value of the parasitic inductance is smaller; the parasitic parameters of the device change nonlinearly with the change of the operating voltage and operating current during the switching process, and it is also accompanied by problems such as an increase in dynamic impedance caused by the capture effect

Therefore, for GaN HEMT devices, it is impossible to accurately characterize and calculate their dynamic switching losses by directly applying the dynamic loss model of Si or SiC power electronic devices.

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