Chip manufacturer from logo?

[robstar]

Anyone know who this is?


It's labeled "U1" and from its placement, i'm guessing it's a voltage regulator.

Thanks!
--Rob*

[marshallh]

Don't recognize, couldnt tell from first glance... Probably an asian fab that is cheap.
What is the background on the rest of the device?

[robstar]

Don't recognize, couldnt tell from first glance... Probably an asian fab that is cheap.
What is the background on the rest of the device?

Cheap is totally the direction to be thinking. The device is a motion-sensing lightbulb fixture that i'm gutting for the PIR sensor. I can't find a datasheet for that either, and was hoping to infer its supply voltage from this chip.

[marshallh]

Well, it could be a fixed linear reg or an adjustable one. Adjustables generally have a coupel resistors sitting next to it.
Look up any generic LDO from National, Linear, NXp, etc in SOT-89 package.
Best to check while running with a meter.
Pinning could be: GND, Vin, Vout but could just as well be several other combos (quite annoying)

[robstar]

Best to check while running with a meter.

Yeah, though this is designed to run off the mains using a light bulb socket, so "while running" will mean a more elaborate operating theater than usual.

[peter.mitchell]

can we see the whole board, so we can rule stuff out ect? see where it sites "in situ"

[robstar]

Sure! Here's the whole thing, just cracked open (didn't have the right screwdriver... oh well


Here's the top of the board with the PIR and leads that would go to the load (a bulb):


Here's the bottom of the board with various ICs (the original mystery one is U1 on the left) and the leads that connect to the mains:

[robstar]

All the example circuits on the web for the BISS0001 show it and the PIRs it reads as being 5VDC devices, e.g.: http://www.e-voron.dp.ua/catalog/016873 has:

[amyk]

http://md-ic.com.cn/datasheet/MD53XX_C.pdf
MD5336 3.6V 500mA LDO
Company: Shanghai Mingda Microtronics Co., Ltd.

[robstar]

Thanks, amyk! Googling for "biss0001 3.6v" (or "biss0001 3.3v") turns up plenty of non-5v "BISS0001" chips. Anyone know the mfr of this one? Looks like a white circle with the top half of an "S" in black on it. (Or maybe that's a final lowercase sigma? http://en.wikipedia.org/wiki/Sigma  Or a stigma? http://en.wikipedia.org/wiki/Stigma_%28letter%29)