外文翻譯---富士igbt模塊應(yīng)用手冊(cè)-文庫(kù)吧資料
2025-01-23 23:26本頁(yè)面
【正文】 ghvoltage / largecurrent handling capacity of a bipolar transistor.Compares the basic structure of an IGBT and a power IGBT is characterized by a p+layer added to the drain side of the power MOSFET is this p+layer that enables the various IGBT features explained in this manual.As shown in ,the ideal IGBT equivalent circuit is a monolithic BiMOS transistor in which a pnp bipolar transistor and a power MOSFET are darlington a positive voltage between the gate and the emitter,awitches on the MOSFET and produce a low resistance effect between the base and the collector of pnp transistor,thereby switching it on.When the applied votage between the gaate and the emitter is set to”0”,the MOSFET will switch odd, causing the supply of base current to the pnp transistor to stop and thereby switching that off as well.This means that an IGBT can be switched on and off using voltage signals in the same way as a power MOSFET. Like the power MOSFET, a positive voltage between the gate and the emitter produces a current flow through the IGBT, switching it on. When the IGBT is on, positive carriers are injected from the p+layer on the drain side into the ntype bases layer, thereby precipitating conductivity modulation. This enables the IGBT to achieve a much lower onresistance than a power MOSFET.The IGBT has a very low on resistance for the following reasons:A power MOSFET bees a singlelayer semiconductor (ntype in the diagram) when it is in the onstate, and has resistor characteristics between the drain and the source. The higher the breakdown voltage and the device, the thicker the nlayer has to be, but this results in an increased draintosource resistance. Thus, as the breakdown voltage increases so does the onresistance,making it difficult to develop large capacity power MOSFETs.Unlike the power MOSFET, the nbase layer resistance of the IGBT bees negligible due to the effect of the pn diode formed by the junction of the added p+layer and ntype base layer when viewed from the drain side. As the ideal equivalent circuit in Fig. 12 shows, the IGBT is a monolithic cascadetype BiMOS transistor that consists of a pnp bipolar transistor and a power MOSFET connected in Darlington form.The device can be pared to a hybrid cascadetype BiMOS transistor that consists of a bipolar transistor chip and a power MOSFET chip. The major difference is the onresistance of the power MOSFET. The onresistance is extremely small in the IGBT. Considering the chip for interchip wiring,the IGBT is superior to the hybrid cascadetype BiMOS transistor.Fuji Electric Device technology (FDT) began producing and
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