So far we've been talking about devices for simulation purposes, and the next topic deals with information manufacturers provide, which is aimed at matching their devices to your application. In a typical catalog, you'll find these devices under discrete semiconductors, where they're at times grouped into either diodes, transistors, and thyristors within specific types of diodes for different purposes, such as switching diodes, rectifier diodes. You can also get bridge rectifiers, as well as diodes that are used as variable capacitors or zener diodes or voltage reference. Thyristors include SRCs, silicon control rectifiers, as well DIACs and TRIACs. Then for transistors, we still have bipolar transistors, MOSFETs, IGBTs, JFETs and HEMTs. Of those, the ones that are of interest to us are primarily the diodes for either rectification or switching, and in terms of transistors, will focus on the MOSFETs in this section. For each of these devices, manufacturers provide devise data sheets and these contain the information that enables matching their devices to your specific application. It therefore list the main parameters that are of interest, what's the maximum voltage, the current, what type of package that would fit your application and enables you to construct the actual circuits. In addition, it also lists to any possible application for their devices as a guide so that you can start from the application and then hone in to a specific device. In addition, most manufacturers also provides application notes where you find a whole more detail as to how the devise can be used in a circuit. At times there are tests circuits provided as well, or a variety of other pointers that are useful when using these devices. Commonly, you also do have then access to the spice models for these devices, so you can then perform circuit simulations. In addition, it also includes detail about the physical structure, the packaging dimensions, tolerances, and at times you also get a 3D model CAD file. Especially for power devices, the temperature dependence and temperature rating are important as these devices tend to dissipate a fair amount of power during operation, and then you would get things like handling instructions or for instance, a soldiering thermal budget as to how long you can heat up the device without destroying it. Let's now take a look at an example and we'll start with a silicon p-n diode. In this particular case, it's 600 volt 30 amp p-n diode, where you get first the key performance and packaged parameters as a quick snapshot that includes the diode name, the blocking voltage, forward current, but also the forward bias voltage of the diodes, and in this particular case also a reverse recovery time, TRR, as well as a maximum junction temperature and a specific type of package. Commonly, you would also get maximum ratings. For instance, the repetitive peak voltage that you can apply is typically close if not equal to the blocking voltage, and then the average forward current that you can tolerate under certain conditions, and that's why they are typically test conditions provided in this particular case at a junction temperature of 123 degrees centigrade. Then distinguishing between average current versus peak surge current or repetitive forward current that you can tolerate in addition to operating and storage temperature of these devices. The second example is for a silicon carbide Schottky diodes and with similar characteristics in this particular case, 600 volt and 20 amp, and what you see right away is that instead of having a reverse recovery time, what is listed here is a stored charge which will have to come back to as we talk about the switching parameters of these diodes, but also a maximum temperature, specific package, and then maximum ratings for this type of a diode looking at maximum voltages, currents under different conditions. In this particular case, power dissipation is added, storage and operating temperature, and also the mounting torque when attaching the package to, let's say, the heat sink. When it comes to a transistors, we find that there are a whole lot more primers that are typically provided, and in part because we're dealing with a three-terminal device, and therefore, we're looking at maximum voltages, for instance, between the drain and the source, between the gate and the source, either as being dynamic applied voltages or statically applied voltages, where dynamic voltages, the ones that are only applied for a short amount of time, are typically higher than the ones you apply continuously. Another maximum rating is the drain current, and in this particular case shown at two different temperatures, but end in a pulse drain current, which can be quite a bit higher and then limited to a certain junction temperature, in this case 175 degrees centigrade. Finally again, we have power dissipation as we had for the diodes. But in addition to the maximum primers, we also have some of the electrical characteristics that are provided, and here it repeats the drain source breakdown voltage, but now it also mentions the threshold voltage of the transistor, ranging from minimum to a maximum value, which then enables the user to build the circuit, such that no matter what the actual threshold voltages of the circuit it would still be functional. We then also have the zero gate voltage drain current, which is a leakage current, which is shown here on this ranging between one or could be as high as 50 micro amps, and then also the gate-to-source leakage current, which is typically in the nano amp range. For most power devices, it's of interest to know what the drain source on the resistances, which was one of the key parameters that a designer would look for for a certain application. Then finally, I have this transconductance, the change in drain current for change in gate voltage shown here on your specific test conditions, namely, specific drain-to-source voltage and specific drain-to-source current.
