Reversely Switched Dynistor Research Articles

A Novel Trigger Method for Reversely Switched Dynistor to Eliminate Residual Voltage in Submicrosecond Pulse Range

A Novel Trigger Method for Reversely Switched Dynistor to Eliminate Residual Voltage in Submicrosecond Pulse Range

Measurement and Analysis for Time Jitter of Reversely Switched Dynistor

To evaluate the application prospects of reversely switched dynistor (RSD) in high-power microwave system, time jitters of RSD were measured, and some factors affecting the time jitter were also discussed. Helping to reduce errors in the results, a way of measuring time jitter of RSD was proposed for the first time in this article. Experiments were carried out, in which dc voltage (main voltage) varied from 300 to 700 V and the energy storage capacitor (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) in the test circuit varied from 2 to 5 μF. Experimental results showed that the time jitter was in the range of 0.57-1.57 ns and changed irregularly with the increase of C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> but tended to increase with the decrease of main voltage. For the relationship between the time jitter and C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , the changing trend of fluctuation of current in RSD is the same as the changing trend of fluctuation of the RSD turn-on delay time and is almost not affected by C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , which indicates C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> has little influence on time jitter of RSD. For the relationship between the time jitter and the main voltage, the decrease of main voltage leads to higher voltage fluctuation of RSD and longer RSD turn-on delay time, which together result in higher fluctuation of current in RSD. Consequently, we believed that the decrease of the main voltage leads to an increase of the time jitter.

PCB-Level Stress Analysis of an Integrated Module Based on Reversely Switched Dynistor

In this paper, the effects of thermal stress and electromagnetic force on PCBs at different frequencies and different pulse current levels in reversely switched dynistor-based pulse power integration modules are studied. According to the theory of the electromagnetic field and thermodynamics, the electromagnetic field and temperature field of the pulse power integrated module are simulated and analyzed by finite-element method. The electromagnetic force and thermal stress on the PCB pad are obtained and their impacts on the pads are compared at different conditions. The simulation results show that the maximum electromagnetic force and thermal stress appear on the pad connected to the capacitor pin. The electromagnetic stress increases with the increase in the amplitude of the current. The thermal stress increases with the increase in the amplitude and the frequency of the current. According to the general specification of the rigid printed circuit board GJB 362B-2009, taken the pull-out force of pads as a standard, the limiting current is determined by the electromagnetic stress at low frequency and by the thermal stress at high frequency.

Redistribution of Current and Loss of Heat in a Reversely Switched Dynistor in the Presence of a Transverse Temperature Gradient

The effects of a transverse temperature gradient in reversively switched-on dynistors have been studied. Taking into account these effects is important for high-voltage frequency dynistor assemblies because of the problems of a distributed cooling of the devices. A simulation description is given for the spatial dynamics of charges and heat in dynistor chips in switching of repeated current pulses. An estimation method is suggested for calculating the maximum repetition frequency coordinated with the heatsink heatsink cooling power.

Positive-bevel edge termination for SiC reversely switched dynistor

The termination structure for the pulsed power switch SiC RSD (reversely switched dynistor) is studied in this paper. According to the structure characteristics of SiC RSD, the positive-bevel edge termination is designed. By establishing the two-dimensional numerical model, the function that the positive-bevel can reduce the surface electric field is proved. Combined the surface electric field and the area loss, 45° positive angle is selected. According to the process characteristics of SiC material, bevel dicing together with ICP (inductively coupled plasma) etching treatment is chosen to fabricate the positive-bevel edge termination in experiment. The forward blocking voltage of about 600V is acquired for the device. The optimal value for the etching depth is also discussed.

Investigation and Comparison on Switching Performance of Semiconductor Pulsed Power Devices

Pulsed power semiconductor devices play a more and more important role in the field of pulse power, with their high reliability and low switching losses. It includes common power semiconductor devices such as insulated gate bipolar transistor (IGBT), thyristor, and reversely switched dynistor (RSD) that is specially applied in the pulsed power area. Two methods of high-voltage differential probe test for single device and ordinary probe test for voltage-divided serial devices were applied to measure the turn-on voltage of these three types of switches in this paper separately. The switching characteristics of the RSD, thyristor, and IGBT were investigated and compared by the turn-on experiments. The advantage of the RSD in the pulsed power application is shown by the experimental data.

Study on Switching Characteristics of Reversely Switched Dynistor With an N-Buffer Layer

In this paper, an N-buffer layer has been introduced into the reversely switched dynistor (RSD). The relationship between the buffer layer and the device characteristics, together with the interaction among structural parameters, is discussed by the orthogonal method in detail. Based on the simulation results, buffer thickness W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> and buffer concentration N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> , N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> emitter concentration N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n+</sub> , and P <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> emitter concentration N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p+</sub> at anode can all affect the maximum turn-ON voltage U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> on the RSD. Furthermore, the U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> increases with increasing W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> or decreasing N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p+</sub> , and if N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> becomes higher continuously, the U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> slightly decreases first, and then dramatically goes up. Besides, the interaction between N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> and W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> has a dramatic impact on the U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> . When N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> = 1E17 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> , W <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n-buffer</sub> = 10 μm, N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p+</sub> = 1E18 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> , and N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n+</sub> = 1E20 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> , U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> reaches its minimum in all the simulations. The experimental results verify the device characteristic's improvement by introducing the buffer layer.

Degraded Switching Characteristics of a High-Current, High-Action Reversely Switched Dynistor

High-voltage, high-current, and high-coulomb transfer closing switches are required for many high-pulsed power systems. This letter presents the degraded switching characteristics of a high-power reversely switched dynistor (RSD). The degraded switching characteristics of the RSD were tested with a working voltage of 10 kV, the repetition rate of 0.2 Hz, and a peak current of about 107 kA. The action is about 1.45 MA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ·s. The transferred charge and energy per shot are about 20 C and 100 kJ, respectively. Only minimal changes in the leakage current and voltage drop were witnessed after a serial test of 50 000 shots. The degraded switching characteristics of the RSD were investigated based on two different methods with the special parameters of static volt-ampere characteristics and dynamic voltage drop on RSD, respectively. The degraded switching model of RSD under high-current conditions for long-pulse application was established using the method of numerical fitting. The results show that these two methods agree well with each other.

Investigation on Switching Energy Losses in Reversely Switched Dynistor

This paper presents theoretical and experimental results on the energy loss characteristics of reversely switched dynistor (RSD) under high-current conditions. Theoretical analysis was performed based on a 1-D modified model by taking account into the carrier-carrier scattering effect and auger recombination effect during the conducting process. The experimental results of energy losses in RSD at various amplitudes of high pulse current were accurately obtained using the direct current injection method. The typical experimental results show that a single RSD has a voltage drop of approximately 9 V with a pulse current of 150 kA, transferred charge of 26.5 C. The theoretical calculated voltage drop based on 1-D modified model is approximately 7.7 V under the same conditions. The theoretical results based on the 1-D modified model almost agree well with the experimental results.

Design and Study on Efficient Triggering Circuit for Reversely Switched Dynistor

The main characteristics of reversely switched dynistor (RSD) are infinite series, long lifetime, turning on in microseconds to nanoseconds, high-current rise rate (100 kA/μs), and ability of passing through large current (several kiloamperes). With these advantages, RSD has a great potential of application in repetition rate pulsed power technology and the future HVdc field. To resolve the problem of residual voltage of RSD caused by insufficient precharge, which leads to nonuniform turn-on of RSD, this paper, based on the conduction mechanism of RSD devices, describes precharge circuit design requirements and establishes a second order circuit model to study the resonant triggering circuit of RSD. It is found that reducing precharge inductor can effectively increase precharge current, resulting in reducing the turn-on voltage of RSD. Finally, design for three improved circuit topologies (full-bridge, intense pulsed, and two-step triggering circuit) are presented and experiments show that these improved circuit topologies can enhance the precharge efficiency and reduce the turn-on voltage of RSD.

Two-Dimensional Numerical Model and Turn-On Performance Simulation of Reversely Switched Dynistor

In this paper, a two-dimensional simulation model of the reversely switched dynistor (RSD) has been introduced in detail. The model has been programmed in MATLAB/Simulink. Different base structures of the RSD are investigated through the model. The relationship between the maximum of turn-on voltage (U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> ) and the base structure parameters have been discussed. When the n-base doping concentration increases, the U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> gets a slow decrease at first and rapid increase around 1.0 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> . The U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> decreases when the n-base width or the p-base width decreases. Especially, a dramatic decrease of the U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Fmax</sub> can be seen when the p-base width decreases to 70 μm. The experimental results of turn-on current and voltage waveforms have been compared with the simulation results to verify the model.

Experimental Study of Reversely Switched Dynistor Discharge Based on Gap Breakdown Load

Breakdown characteristics of a gap breakdown load was investigated in this paper, and a reversely switched dynistor (RSD) discharge circuit was designed based on the load. Based on the characteristics of the load, the RSD discharge circuit was improved and optimized. The volume of the magnetic switch was reduced. To protect the thyristor and RSD, a diode was anti-parallely connected with the thyristor, which reduced the time requirement when a power voltage was applied to RSD. Experimental results show the circuit designed in this paper can switch a high voltage and high current smoothly, and allows the power voltage to change in a wider range.

Thin emitter structure improved turn-on characteristics in RSD

The thin emitter structure was introduced into reversely switched dynistor(RSD) to improve its turn-on characteristics. According to the analysis of turn-on condition, thin emitter structure is capable of reducing the extraction action for the triggering plasma layer P1 during turn-on process, and satisfying the requirement that triggering electric charge cannot be exhausted and therefore enables RSD to turn on uniformly. The on-state thin emitter RSD was equivalent to an asymmetric pin diode model. The simulation result shows that the forward voltage drop of RSD falls with the decrease of doping dose in p+-emitter in a certain range, and when the doping concentration is extremely low, the decrease of the width of p+-emitter can obtain a low forward voltage drop. Thin emitter RSD chips were made by sintering Al on n-Si. The test result shows that their turn-on process is uniform and the voltage drop is 7.5 V when the peak conversion current is 5 500 A.

A High Power Semiconductor Switch RSD for Pulsed Power Applications

High power switch is one of the most important components in pulsed power technology. The RSD (Reversely Switched Dynistor), turned on by a thin layer of an electron-hole plasma, is a high power semiconductor switch. In this study, the RSD turn-on conditions were investigated by numerical analysis and device simulation as well as the experiments conducted to validate the turn-on conditions. A design of a triggering high-voltage RSD is presented based on a saturable transformer.

Single shot and burst repetitive operation of thyristors for electric launch applications

Electric gun applications require switches with simultaneous high peak currents, di/dt, and action capability. The development by Silicon Power Corporation (SPCO) of a 125 mm diameter symmetric thyristor which utilizes a unique compact package with decreased thermal resistance from junction to sink has addressed the thermal resistance problem and conduction area limitations. The development of the reversely switched dynistor (RSD), an asymmetric thyristor, by the Ioffe Institute in Russia, has addressed the commutation power dissipation problem by using a unique and highly interdigitated gate structure in the anode and a high current driver. Tests were conducted on both types of devices by discharging a low impedance pulse forming network (21 mF or 17 mF total capacitance) via the device under test into either a matched load or a short. Test peak current varied from 151 kA to 221 kA. Testing was performed, in the same test circuit as the 125 mm thyristor, on an 80 mm diameter RSD. The paper places in perspective the overall performance of these devices and the implications for future designs and applications. The implication of this work is that combining the design principles of both types of devices to the solution of the thermal limitations of thyristors could increase the peak current capability of a 2.5 kV 125 mm symmetric thyristor by a factor greater than 2 and the di/dt by an order of magnitude. Specifically, the thyristor should reliably switch, into a shorted load under repetitive conditions, a 0.5 ms duration pulse with a peak current of 400 kA and a di/dt of 25 kA//spl mu/s.

Generator on the basis of reversely switched dynistors forming pump pulses for a copper-vapor laser

A generator designed on the basis of reversely switched dynistors and forming pump pulses for a coppervapor laser is described. The operation of the circuit is considered in detail. Its main components are a low-voltage high-current switch operating on the basis of a reversely switched dynistor (RSD), a step-up pulse transformer, and a system for magnetic compression of pulses. It is shown that a RSD makes it possible to increase the efficiency and decrease the dimensions of the generator in comparison with thyristor systems. Pulses of electric current through the active element of a copper-vapor laser with a 40-ns leading edge and a repetition rate of 8 kHz are formed. Laser radiation with an output power of 2 W is obtained.