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Thread: What are Some Important Things to Look at on Spec Sheets?

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    Default What are Some Important Things to Look at on Spec Sheets?

    Spec sheets are awfully confusing. I'm talking about rectifiers and such things when I open up these cheap units. I would like to be able to say some stuff about them, but I am clueless as to what I should be looking at on the spec sheets.

    So for example, here is one of the rectifiers in the Logisys PS480E12: http://www.st.com/content/ccc/resour...CD00000820.pdf

    How I am supposed to identify what exactly it is rectifying? There is also this rectifier, for instance: http://psu.guru/datasheets/STPR1620CT.pdf

    I see this on a lot of power supply reviews, these parts, these MOSFETS and Schottkeys and listed in the review with the spec sheet in the form of a link, but nothing is said about those parts. Are they good? Are they bad? How does it compare to what it on the label of the power supply? That is precisely what I would like to be able to identify when it comes to rectifiers and switching transistors.

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    Default

    Datasheets can be the best thing in the world, or the most frustrating thing when building something.

    Simple explanation:

    If you are reviewing/tearing down something, you can see if the company is marketing it right etc. It's almost impossible to get bad and good brands of silicon like that, because you can't open up a shop that sells mosfets that fail suddenly like caps on the side of the road. You could try rebrand things with a laser etcher, but your thing won't work, and you'll have customers smashing you on the head with their reels of dead components (read https://www.sparkfun.com/news/350)

    One thing you can see is loads, etc. If your 12v rail only has 1 15a mosfet , and your power supply is advertised as 800w, it's a easy way to see that theres no way that your power supply will be able to handle that amount of power drawn.

    Datasheets also list temperature curves, and it shows that you should probably use a heatsink for that flopping to-220 package that has 20 amps going through it. Usually you can also see how to design a sample circuit if you were building your own project, as there's application examples.

    For some components, the internal resistance is also quite important. This can mean the difference between using a heatsink for that component and not, or if your power supply hits 90+ Uranium-238 or 80+ bronze


    Modern day electronics have a TON of surface mount components. Who cares about that? Well it's super easy and cheap to solder when done correctly. However, when you have to design the pcb for all those components, you have to get the drawing/the pads correctly stenciled onto your pcb. So the datasheet can show you all the technical stuff, the drawing etc. You can also see their manufacturing tolerances etc etc. Basically the datasheet has everything the manufacturer puts to use the component correctly.


    Datasheets are super useful when you're designing a product that must do x y and z. They help you find the perfect component you need. It's basically a instruction manual for electrical components. It shows everything you need to know about the chip. What it can handle, speed, temperature and more.

    Super useful for designers/engineers. Not very useful for the modern day consumer though.

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    Default

    See but I have trouble just finding the amperage of some mosfet. Going back to my one spreadsheet http://www.st.com/content/ccc/resour...CD00000820.pdf

    Are you able to tell me what the above does and how many amps it is rated for?

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    Good place to read. http://www.microsemi.com/document-po...eet-parameters

    Your schottky diode rated current drops when the temperature increases. So you'll have to calculate the max amperage at x temp by using some math.
    Last edited by ridgid13579; 07-04-2016 at 02:25 PM.

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