A1712 P-Fet

[justDIY]

I harvested a few p-channel fets from a piece of power management pcb.

they are in an SOIC 8 package, markings:

A1712
S843

From the way they were wired, I'm certain they are fets and pretty sure they're P-fets, but other than this, I dont know anything else

google's not being a lot of help, I'd just like to know their ratings.

I tried searching Allegro and Analog neither have any fets matching that number ... any other suppliers with an A name?

 

[on1aag]

P-channel MOSFET.

Hi JustDIY,

A quick search gave me the following link for the µPA1712:

http://www.eu.necel.com/_pdf/D11495EJ1V0DS00.PDF

But when I entered S843 my crystal ball went dark.

After I replaced the battery of my crystal ball I found the other
one too:

http://www.fairchildsemi.com/ds/ND/NDS8434A.pdf

on1aag.

 

[justDIY]

I'm gonna go with your first hunch, the NEC ... especially since it mentions lithium protection / notebook power in the applications - that's exactly the circuit I extract it from

I did find that fairchild part searching those numbers on digikey, I guess the chip could be either, the ratings are fairly close... it could be neither as well, only one way to find out!

thanks!

 

[Sceadwian]

If you can't find rateings you can always just set up a thermosistor coupled directly to the fet set at a typical over heating temperature and gradually increase the amperage through it till it starts overheating.

 

[justDIY]

If you can't find rateings you can always just set up a thermosistor coupled directly to the fet set at a typical over heating temperature and gradually increase the amperage through it till it starts overheating.

I was more worried about the voltage ... I don't think they overheat with too much voltage, they just breakdown, permanently?