Seems to be a logic level parthttp://www.irf.com/product-info/datasheets/data/irf9540n.pdf
no matter what component here, the current passing through it will greatly vary (from 0.02A to 1.28A), which means that its voltage drop may also significantly vary
Quote from: CrossRoads on Dec 29, 2012, 10:53 pmSeems to be a logic level parthttp://www.irf.com/product-info/datasheets/data/irf9540n.pdfNo, it is most definitely not a logic level part. Rds(on) is quoted at Vgs=10V only. It might just work @ 1.28A, it depends on whether the part you get has a higher or lower than normal gate threshold voltage, whether the 5V supply is a little higher or lower than normal, and on the temperature. Bad choice for this project.
If I do some 12v stuff (like putting LEDs on cars), would the be good for that?
Lets use 20 mA x 64 LED as an example. Assuming its running on 5v, using constant current driver to sink, (that sounds like the direction he is heading), it should use up to 1.28A. With this design, he is only doing 12.5% duty cycle. How do we apply the math to figure out what specific specifications to look for, and ranges maybe? It seems like a simple table would be easy enough to make.