EEVblog Electronics Community Forum

EEVblog => EEVblog Specific => Suggestions => Topic started by: dragon-architect on March 01, 2017, 11:11:19 pm

Title: Fundamentals Friday - Mosfet Body Diode
Post by: dragon-architect on March 01, 2017, 11:11:19 pm
So, last night and today, a friend and I got to talking about this ElectroBOOM article (http://www.electroboom.com/?p=914) (yes, I watched the video; yes my heart skipped beats every time he made sparks fly; dear god I just can't with this guy x.x) about taking advantage of the body diode in a MOSFET to trigger a reverse polarity protection circuit. The conversation led to this question on the electronics stack exchange (http://electronics.stackexchange.com/questions/15106/source-vs-drain-polarity-for-mosfets) and today I found this two part article about mosfet design basics: Part 1 (http://electronicdesign.com/power/mosfet-design-basics-you-need-know-part-1) and Part 2 (http://electronicdesign.com/power/mosfet-design-basics-you-need-know-part-2).

And while all of this looks really cool and radical, and the body diode just comes up as "part of how a mosfet is made", I'd like to suggest a Fundamentals Friday episode about how the body diode works in a mosfet, and how it can be used if it's internally (or even externally) connected to source or drain. Apparently if the diode isn't internally connected, a mosfet can conduct in both directions when switched on. So... why is the diode internally connected in the first place?

I could probably go on with questions, and it'd be awesome if Dave could do a FF episode all about this! :D
Title: Re: Fundamentals Friday - Mosfet Body Diode
Post by: Random Model Maker on March 14, 2017, 09:52:00 pm
In that context I would think that it would also fit in to talk about SCR latchup