Papers by Keyword: Fast Switching

Abstract: With the capability to switch at high speed, there are important concerns about Parasitic Turn-On (PTO) when using SiC MOSFETs in switching applications with fundamental half-bridge configuration [1]. In this work, we present 1200V SiC planar MOSFETs with low specific ON-resistance (Rsp), fast switching characteristics and high immunity to PTO. The PTO immunity is verified by experimental comparison to several commercially available SiC MOSFETs.

Abstract: The resistance of the BJT collector layer can be sharply reduced by the effective injection of minority carriers (holes) from base to collector. As a result, the voltage drop across the BJT becomes substantially lower. The conditions under which this process can occur are the short rise time and the high amplitude of the base pulse.

Abstract: A new rectifier, called SPND or SNPD (Schottky-PN or -NP junction diode) and inherently showing low on-resistance and unipolar operation, was experimentally demonstrated for the first time on 4H-SiC. It is structured with an n^– or a p^– region of very low doping that is sandwiched and completely depleted between a Schottky junction and a one-sided PN junction. Either electrons or holes, but not both, contribute to the current conduction process. Clear and sharp rectifying properties are observed over the entire range of applied voltage.

Abstract: The paper presents constructive scheme, the mathematical model and schematic diagram of the hydraulic rotary control valve of the pneumohydraulic impact unit. Detailed analysis of the mathematical model was made for the purpose to create modes of the movement conducive to improving the work of pneumohydraulic impact unit at the point of switching. The results of mathematical modeling (schematic diagram of matlab) are given.

Abstract: Considering the development of faster power electronic switches, especially silicon carbide (SiC) devices, parasitic elements, such as stray inductances and capacitances, become more and more crucial. Overvoltages caused by stray inductances in combination with fast switching transients can destroy the devices at turn-off. In this paper the implementation of the DVRC circuit for silicon carbide bipolar junction transistors (BJTs) is investigated. The DUT was Fairchild`s FSICBH057A120 (V_CES = 1200 V, R_on = 57 mΩ).

Abstract: This paper analyzes the voltage quality problems on transmission line of 10kv distribution network, and then introduces a series compensation device, which is based on fast switching and can effectively solve the above problem. Furthermore, this paper calculates the voltage under a actual situation, which fits the expected results.

Abstract: In this work we have demonstrated the operation of 600-V class 4H-SiC vertical-channel junction field-effect transistors (VJFETs) with 6.6-ns rise time, 7.6-ns fall time, 4.8-ns turn-on and 5.4-ns turn-off delay time at 2.5 A drain current (IDS), which corresponds to a maximum switching frequency of 41 MHz – the fastest ever reported switching of SiC JFETs to our knowledge. At IDS of 12 A, a 19.1 MHz maximum switching frequency has been also achieved. Specific on-resistance (Rsp-on) in the linear region is 2.5 m
·cm2 at VGS of 3 V. The drain current density is greater than 1410 A/cm2 at 9 V drain voltage. High-temperature operation of the 4H-SiC VJFETs has also been investigated at temperatures from 25 °C to 225 °C. Changes in the on-resistance with temperature are in the range of 0.90~1.33%/°C at zero gate bias and IDS of 50 mA. The threshold voltage becomes more negative with a negative shift of 0.096~0.105%/°C with increasing temperature.