Hello and welcome to my online course entitled Introduction to power switches. My name is Bart Van Zeghbroek. Before diving into the actual course material, I'd like to give you a quick overview of this course and it's place in the power semiconductor device specialization. The overall objectives of this specialization is for you to gain understanding of power semiconductor devices, as well as to gain some practical knowledge. In terms of understanding, we'll need to take a look at the semiconductor physics and from the physics we'll come up with physical models as well as circuit models as will be used for simulations. In terms of practical knowledge, we'll take a look at device datasheets, then also perform some device simulations using LTSPICE and then analyze the devices in circuits based on the simulation results. Finally, we'll take a look at both packaging and thermal management. The way this specialization is organized, it's essentially a top-down approach. We'll briefly talk about some power systems looking at power generation, the need for power conversion, and then also the end-uses of different types of power, but then quickly move on to the different power conversion circuits that include rectifiers, on-off switches, DC to DC converters such as buck and boost converters, as well as DC to AC converters, which we refer to as inverters and a specific case would be a variable frequency converter. It is these types of circuits that have been enabled by semiconductor devices. The devices of interests are therefore diodes, MOSFETs, IGBTs, but we'll take a look at some other devices as well. To fully understand these devices we'll have to dive into the device physics and we'll have to come up with concepts such as an energy band diagram, but then will quickly move on to identify both the current voltage as well as the capacitance voltage characteristics of both diodes, transistors, and other devices. Given that we're dealing with power devices, it's also important to take a closer look at the breakdown characteristics within the semiconductor, as well as the temperature dependence of a variety of the semiconductor parameters. From the device physics, we then come up with the equivalent circuit models that can be used in simulations. We can compare those then with device data sheets and then start performing both DC and transient simulations. Then from the simulations we can then extract the switching performance we're primarily interested in the power losses in the devices and in the circuits and we'll distinguish between on-state losses as well as the switching losses in a particular circuit. This then closes the loop because these losses become than the losses in the power system, which is what is of interest from both a generation, a conversion, and user point of view. The power semiconductor device specialization consists out of four courses. In this course, introduction to power switches is the first one of the series. The second one takes a deep dive into the high voltage Schottky and p-n diode whereas I've mentioned before, we need to take a closer look at semiconductor physics from there we can build a model, but then also look at specific power diode issues. Next are different types of switches such as transistors, latching devices, and power modules with a focus on MOSFETs, metal oxide, semiconductor, field effect transistors, and IGBTs, insulated gate bipolar transistors. Then the last course in the series focuses on power device fabrication where part of that is looking at the fabrication of the integrated circuit, that is the power device, but then also the packaging of these chips, as well as building modules that contain multiple die in a single package. Then finally the corresponding thermal management. Let me provide now some more detail about this first course. This course consists of four modules, and the first one covers some power device basics. We start from the need for power conversion, the corresponding power conversion circuits that are of interest, and then also the devices that are used in the circuits, their characteristics, as well as their classification. The second module is our first look at key power devices. We'll be looking at these devices primarily from a structure and operational point of view first and then also look at the corresponding simulation models and perform some simulations. In Module 3, we examine power device data sheets and we'll separately take a look first at the DC parameters that are contained in these datasheets, but then next also to switching parameters which are equally important as well as the temperature dependence of the device parameters. Then the last Module 4 there we'll take a look at power switching examples starting off with the power dissipation simulation of individual devices, both diodes and MOSFETs and then using a boost converter as an example to further examine the device performance in an actual circuit. Let me close by welcoming you once again to the introduction to power switches and I hope that for you this course will be a worthwhile educational experience.
