Comment on Resistor/Capacitor broke off, anyone knows if it matters?
dave@feddit.uk 1 week agoFrom the TI briefing note:
Paralleling power metal-oxide semiconductor field-effect transistors (MOSFETs) is a common wayto reduce conduction losses and spread power dissipation over multiple devices to limit the maximum junction temperature.
It would also provide redundancy in case of a failure—if you had only one, and it failed (or was scraped off by an over-enthusiastic GPU installation), you would probably not be going to space today.
Can you link that note?
I think that’s usually the method in high power applications where heat dissipation is paramount. Each of these diodes is only rated for 210mA of drain current. From a BOM cost perspective, it’d be much cheaper to just buy one 5A FET rather than parallelizing a bunch of 0.21A FETs. That 5A FET would be in a package that could handle whatever heat it generates.
You’re probably right—I searched for ‘20 mosfets in parallel’ or something like that and it came up near the top. But I didn’t read the whole thing.
I guess there’s got to be some reason for using so many though?
great_7562@ani.social 1 week ago
So I guess, what this means is having one scrapped off or failing isn’t a big issue (because of built-in redundancy accounting exactly for that)?
dave@feddit.uk 1 week ago
My gut feeling is they didn’t put 20 there in case you scraped one off. But likely the others will have enough leeway to cover for it. If the power rail gets stressed enough, it might well fail sooner than it would have.
ch00f@lemmy.world 1 week ago
My other running theory is that (due to relative proximity to audio chip), they’re muting FETs for muting audio channels when connecting headphones/speakers to prevent speaker pop.
dave@feddit.uk 1 week ago
Interesting. Is the orange line on the board separating the audio section from the rest?