I need help with mosfets, I’m new to the electrical engineering and have run into a question that I haven’t been able to find a clear answer to. My sons hoverboard got wet the other day and wont turn on. I opened it up and started testing things and found that 6 of the 12 mosfets (all the ones on the right board) are bad (tested with D and S pins). The original part number is CS48N78. The only ones I can find are in china, and when I emailed the company they said freight shipping would be more than the parts are worth. They offered the information that the STP75NF75 would be an equivalent replacement. When I pull up the data sheet for the two, there are things that are different. My big question is this: Can someone give me a basic rundown of what the specs mean and the differences between the two? ( I have a basic understanding of how mosfets work but that’s it) Basically, I need to know what I am concerned about and what is ok to be a little different. I don’t want to damage anything else if the part is not correct… I am also curious if there is anything else I need to check before I put it back together. Thanks in advance for the help!
Hello jacobhilt,
Thank you for your inquiry.
The recommended replacement has a slightly lower gate/source voltage. +/- 20V vs. +/-25V.
The only other thing that stands out is the recommended replacement has a higher RDS-On resistance of 11mOhm vs. 7mOhm, but this spec is pretty close.
We’re not going to be able to coach on what this all means, here’s a brief overview on our forum of transistor replacement specifications:
Overall the recommended replacement looks close in spec and a candidate for a potential alternative but without knowing details about exactly what kind of circuit this is going into we’re not going to be able to say one way or the other if it will work, most importantly, the pin outputs match up, we always advise our customers verify replacements through the manufacturer’s datasheets/specifications.