Parallel Technology Of High-power Devices Based On Drive Timing And The Match

With the development of power electronics, power electronics devices put forward increasingly demanding for high power output and the ability of current and voltage capability of semiconductor power devices. When designing the high capability devices and high current capability is needed, generally a high current capability device is selected or many low current capability are selected. The method through parallel devices controlling high current is sample, cheap and welcomed by the market.Due to circuit parasitism and the variations in manufacturing process, the device electrical characteristics and drive signals is unbalanced, which will influence the distribution of current and reduce the reliability of device. Uneven distribution of current require derating for device, so the current capability is wasted and the lifetime of device is reduced. Although parallel devices can increase current capability, but many measures are needed.In this background, the paper analyze the factors causing uneven current, the theory of many measures for distribution of current and their advantages and disadvantages. In order to solve the uneven current of high power devices, a program is proposed, and then the theory and structure of the program is given.The circuit resolving uneven current proposed in this paper is designed with the 1um, 40 V high voltage process. Combined with the theory and structure of the program, firstly, circuits of the chip are designed and simulated, which include current controlled, driver, reference voltage with fifth-order temperature compensation, reference current, over-temperature protection and under-voltage protection. After the circuits pass simulation, the overall chip is simulated and the affect of parallel current is observed.In the function of this chip, the situation of static uneven current is reduce from 5.27% to 0.396%. The peak current of turning off is reduce from 22.79 A to 7.546A(the average current is 7.325A). The Synchronous current of turning off and turning on is significantly improved.