what IC is this?


Joined Oct 26, 2011
To me it looked like a transistor so, I googled: surface mount transistor identification
This led me to: elektronik.googlecode.com/files/SMD_Catalog222.pdf
Under "GG" there were 3 choices--since it appears to be a SOT89, I googled: BAW79C
This led me to alldatasheet.com--in the middle of the page click on the link: BAW79C to view the pdf file
Sure looks like the correct one--hopefully, that is all that is wrong with your board

The "47K" could indicate a date or lot code ???


Joined Feb 20, 2011
I didn't look up the part, but it could also use a 47k internal resistor.
A resistor with 4 pins? I think a transistor is more likely. Besides, SMD resistors use number codes to give the value. I have yet to find one that simply says 47K for a 47 kilohm resistor.

Personally, I'd agree with Jim on this one.


Joined Apr 11, 2010
If you do look up the part, jimkeith's process leads you to a description of a dual-Silicon Switching Diodes SMD part (For high-speed switching High breakdown voltage Common cathode). Not resistors; not transistors.


Joined Jul 17, 2007
The datasheet you attached is for an IC that has 54 pins. That's just 50 more pins than the package in question.

For the SMD references I have, BAW79C is the only device that has the same package, and as has already been reported it's a dual diode 200v common cathode.

But, my reference is a couple years old, and it's possible that a manufacturer used GG for another part. What causes me consternation is that the reference designator is Q903; the leading Q normally indicates a transistor of some variety; this reference designator should begin with "D". However, Q901 is the same part, so if one is careful, Q901 could be removed at the same time and tested.


Joined May 11, 2009
My Turuta SMD-codes data book have these marked as GG and SOT-89 package
GG 2SA1369-G Si-pnp AF-Drv, 30V, 1.5A, 500mW, B=400..800, 90MHz SOT-89
GG BAW79C Si-diode Dual, Sw, 2x200V, 1A, <1000ns SOT-89
GG RT9161A-45CX LVR-IC LDO, 4.5V±2%, 500mA SOT-89​
GG– RT9161A-45PX LVR-IC LDO, 4.5V±2%, 500mA
I found the 2SA1369 data sheet here http://www.datasheetcatalog.org/datasheets2/15/151654_1.pdf It looks kind of correct. Without saying it is your component 100%.
Last edited:

Thread Starter


Joined Dec 28, 2011
And the winners of the Mistery IC Award are (drumroll please) t06afre and SgtWookie.

At first I also thought it could be a BAW79C but after testing the IC it was clear that it wasn't a diode switch but a pnp.

It's a 2SA1369 for sure. I already replaced it and everything is ok now.

Many thanks to everyone for the amazing help.


Joined Feb 19, 2009
The codes are the one thing that really bug me about SMD.

Many times, transistors are too small to write anything on, other than a microstamped letter, which is nearly useless.

Or nothing at all, like the ones to the right of the transistor in question in the original image.