Identify Unknown IC (reverse engineering)
SRLM
Posts: 5,045
Can anybody identify either of the ICs on the board? I'm looking for a datasheet of some sort, or at least a part type. This is an eagle tree brushless rpm sensor, eg http://www.hobbyking.com/hobbyking/store/__4635__MicroPower_Brushless_Motor_RPM_Sensor.html
The board is single sided, and about the size of a #2 pencil eraser.
The board is single sided, and about the size of a #2 pencil eraser.
Comments
Drat, none of the devices listed has a 6 pin footprint. This isn't as much fun as it looks.
A. How should I know?
B. Suggestions of all sorts of web searches that might help.
But there is a C. and that is the most reliable reply.
C. Reverse engineer the whole board.
You appear to have only 5 wires and two are likely to be power, not signal. Alternative, there is not actual power required and you have an input and an output.
In reverse engineering context and general knowledge are everything. Just looking at your ICs tells a lot. One is 6 pin and the other is 3. Neither is likely to be a logic chip as those tend to have 14 pins or more. And there are not six pin common microcontrollers.
So what are they? Transistors in IC packages or MOSfets. Maybe an opto-isolator.
Try to draw out a preliminary schematiic and apply some real electronic fundamentals and you should get the answer you want. I have had a lot of success with reverse engineering of many things more complex than this. Hewlett Packard refused to provide info about what chips they were using, but nonetheless I was able to easily service their terminals by determining which pins were the power supplies and the which were the crystal. Together it was obvious that they were using Z80 chips - replacement proved me right.
This is a tiny reverse engineering project and very easy to do - much easier than than a Sunday Suduko puzzle. Have fun with it and you will find it rewarding.
My first impressions are that it is taking the 50 cycle per second PWM signal and converting it to a useful analog output.
BTW, that marking certainly does look like B5 on the six pin
http://www.rcgroups.com/forums/showthread.php?t=1006124
-- Gordon
When we copy, it's called "reverse engineering".
Sure sounds better, huh?
And no, I'm not picking on SRLM, I'm just pointing out America's favorite rationalization and buzzword. There's even http://www.reverseengineeringoutsourcing.com ! Copy someone's design and outsource jobs with just one click! Now THAT'S American innovation at its finest!
It's one thing to figure something out you have in hand and make use of it. It is after all your to do with as you see fit as the owner of the device. Quite another to rip off someone elses design and replicate it to their loss; that is a foul no matter who or what. One exception to my last statement would be for an truly orphan part that there is no other way to obtain.
Frank
Agreed, Frank. Times HAVE changed. 'Cuz that definitely wasn't the prevailing US attitude back in the 1970's when the first waves of Ter-yotas & Datsuns were rolling into Anytown USA.
No no no.
That site is evil.
They got to where they were by messing with the Google search results algorithm.
They would just randomly throw up sequential part numbers (like 74LSxxx and such) all on one page, and then have individual pages with those names, even if they didn't have a datasheet. Plus they would and probably still do modify the datasheets with a message saying where you downloaded it from, plus who knows what else.
The markings on the chips aren't detailed enough to use them in an online search to figure out what they are unless you just happen to work with them.
Rick
I had to design a dead reliable zero crossing detector and I referred to the National datasheet for the LM139 and implemented an enhanced version of the single supply detector. Even at tiny voltages, the detector was super reliable.
I traced the connections as best I could, and did an overlay for the image. Most of it appears to be straight forward, except for three components that don't seem to have any resistance. These components have a grey-ish color on top. The other components are tan or black.
Does anybody know how this circuit works?
Important! The colors don't mean anything special, it's only there to prevent confusion for when two traces pass over one another. Two separate traces of the same color are not connected.
For those who can't read it, it looks like the top chip marking is either B599t or B566t. The 99/66 is rotated 90 degress, so it could be either. The bottom chip is AA4H.
BTW, is the image in the first post exceptionally large for anybody? My browser (Chromium) automatically downsizes it.
-Phil
At least here in the U.S. if you rip off the IP of say Apple or any other business you get torn apart in the courts for it. Doubt it, try ripping off say Parallax and see what happens.
In regards to the American companies who do business in China, they deserve the Chinese ripping them off. Lay down with dogs and you'll get fleas.
Couldn't agree with you more, but from a different perspective. I am so tired of buying "Made in China" Smile and having to return it when it fails that I am boycotting the companies (as much as possible anyway) that have it made there. Not possible to avoid all of it of course since so much is made there by short sighted organizations.