The self-heating and high-power microwave (HPM) effects that can cause device heating are serious reliability issues for gallium nitride (GaN) high-electron-mobility transistors (HEMT), but the specific mechanisms are disparate. The different impacts of the two effects on enhancement-mode p-gate AlGaN/GaN HEMT are first investigated in this paper by simulation and experimental verification. The simulation models are calibrated with previously reported work in electrical characteristics. By simulation, the distributions of lattice temperature, energy band, current density, electric field strength, and carrier mobility within the device are plotted to facilitate understanding of the two distinguishing mechanisms. The results show that the upward trend in temperature, the distribution of hot spots, and the thermal mechanism are the main distinctions. The effect of HPM leads to breakdown and unrecoverable thermal damage in the source and drain areas below the gate, while self-heating can only cause heat accumulation in the drain area. This is an important reference for future research on HEMT damage location prediction technology and reliability enhancement.

The anti-ESD characteristic of the electronic system is paid more and more attention. Moreover, the on-chip electrostatic discharge (ESD) is necessary for integrated circuits to prevent ESD failures. In this paper, the mixed TCAD model of the ESD protection circuit is built and simulated, and the negative transmission line pulse (TLP) injection damage experiment is carried out on the CD4069UBC chip. The circuit model consists of three-dimensional shallow trench isolation (STI) diode TCAD models and a three-dimensional multi-gate Complementary Metal-Oxide-Semiconductor (CMOS) inverter TCAD model. Moreover, the TCAD modeling is based on a 0.25 μm technology node. Through the transient simulation of the electrothermal coupling, the electrical signal of the input and output nodes of the circuit and the distribution of the electrothermal parameters in the device are obtained. Moreover, by analyzing the simulation results, the physical phenomena and the mechanisms of interference and damage mechanism during TLP injection are explained. The location and type of diode damage in the TLP injection simulation results of the circuit model are consistent with the TLP experiment damage results. The proposed ESD protection circuit model and analysis method are beneficial to ESD robustness prediction and ESD soft damage analysis of IC.

This article proposes a triple-mode modulation wide input voltage range DC-DC buck converter using adaptive power transistor width (APTW) technique, which can be used in low-power applications such as the Internet of Things and automotive chips. This buck converter operates in PWM mode under heavy loads and switches to PFM mode under light loads. Using a load current detection circuit, it enters power-saving mode (PSM) at extremely light loads and adaptively adjusts the power transistor width to minimize circuit losses. The proposed buck converter is designed using a 0.18μm standard CMOS process. Simulation results show that when a 12V standard input voltage is used to generate a 5V output voltage, the efficiency reaches up to 94% for load currents in the 1mA-1A range, and the converter maintains a high efficiency of 80% at light loads of 1mA.

This study examines the instantaneous failure mechanism of high-voltage multilayer ceramic capacitors (MLCCs) through pulsed discharge testing, vibration testing of MLCCs, and piezoelectric coefficient measurement with mechanical characterization of the ceramic dielectric material. The results point out that the instantaneous failure is caused by electromechanical coupling effect of the ceramic dielectric material. The MLCC in the alternating current (AC) electric field vibrates with the oscillation frequency of the discharge current. When the frequency approaches or coincides with the natural resonance frequency of the MLCC, mechanical resonance is induced. This significantly amplifies the flexural stress within the internal ceramic layers, ultimately leading to dielectric fracture. If the flexural stress remains below the characteristic fracture strength of the material, failure typically occurs due to cyclic fatigue. In contrast, when the stress exceeds this threshold, fracture results directly from transient high stress. This study contributes to the reliability-oriented design of MLCCs, and the related testing methodology can also be extended to investigations of other dielectric materials.

The electromagnetic field emitted by the trigatron switch (TGS) can cause electromagnetic interference in nearby electronic devices. According to the breakdown sequence of the main gap and trigger gap, the breakdown of TGS can be divided into two modes. This article innovatively reveals the significant differences in the amplitude and peak frequency of the radiated electric field between the fast and slow breakdown states of the TGS from the perspective of transient electric field response testing. The experimental results show that the average electric field amplitude of the fast breakdown mode (FBM) is 2.96 times that of the slow breakdown mode (SBM), and it is in good agreement with theoretical predictions. The time-frequency characteristics were compared through wavelet analysis. The results indicate that high-frequency components are concentrated at the moment of gas gap breakdown. The peak frequencies in FBM and SBM are 100 and 67.5 MHz, respectively, and the concentration of high-frequency components is more pronounced in FBM than in SBM. These findings provide guidance for optimizing the operating conditions of TGS in different electromagnetic compatibility (EMC) application scenarios and strongly support accurate EMC analysis and design.