Not a bad idea of course, when I was using the wrong units it was just really confusing to me where 0.18 came from. Now that I realize my mistake your logic is clear!
I fished around on the internet a little and it seems that the “LEDA” chip is definitely the QX9922.
http://club.dx.com/forums/forums.dx/threadid.1205677
[quote=desolder]
It’s the QX9920:
http://www.szroya.com/uploadFile/download/200886204048427.PDF
The IC is rated for 24V, but the input capacitor is only rated for 16V. So it appears the “5V-12V” description is the correct one.
If anyone is curious, here’s the thread claiming that it’s the QX9920, apparently from a representative of the company:
http://translate.google.com/translate?hl=en&sl=zh-CN&u=http://bbs.dianyuan.com/topic/581194&prev=/search%3Fq%3DLEDA%2BSOT-23-6%26hl%3Den%26client%3Dfirefox-a%26hs%3DuZE%26rls%3Dorg.mozilla:en-US:official%26prmd%3Dimvns&sa=X&ei=S0cUUPWkOcbsqAGBl4CYCw&ved=0CFoQ7gEwAAp
[/quote]
desolder is misleading when he says that the chip is rated for 24v, the chip can run on 2-6.5v. The diagram in the datasheet shows a 2.5v - 5.5v Zener Diode in use along with the appropriate resistor in order to keep the chip inside that range.
No doubt that's what some of the extra stuff on the PCB in this thread is. I don't see the advantage of QX9920 over QX5241.