Identifying a DFN 8 buck converter.

[Fflint]

I've been trying to identify this dc-dc (likely buck, or buck boost) converter with AMGM317 written on it for a while, but I found nothing else than some guy asking the same question (and getting no answer) on a Russian language forum.

I'm attaching his pictures (as they're better and it shows the underside) and a drawing of how it is used (this is exactly the same in my board).

This part is on a Chinese made flight controller for an rc plane/quad/car. There are 2 of them one for 5v the other for 9v.

If anyone knows the part number, please let me know.

I do not understand what the manufacturers gain by obfuscating their parts like this. There is enough space on this chip for 3 rows of 4 characters each. They could've put the actual part number there. Why do I think AMGM317 is not the part number? I searched for it with phrases like dc converter etc (including in Chinese) and I found nothing.

[DavidAlfa]

That line at the top was familiar to me from Monolithic Power.
Quickly checked their catalog and indeed, seems to be a MP9943, marking is AMGY (Y = Year), Datasheet.

[Fflint]

Wow, that was quick, thank you 

I wish there was some sort of database where you could look up a chip by its markings.

[DavidAlfa]

There're are a lot, but chinese ICs are usually not there.

https://smd.yooneed.one/
http://www.smdmark.com/en-US
http://www.marsport.org.uk/smd/mainframe.htm
Also check smd codes data book:  link

[fzabkar]

Another one ...

http://markingcodes.com/search/c/amg