Have no idea of what chip it is.

Hi Luxing,

If you go to any Product folder page, click on the Order now tab, then under the Device marking column click View.  In the new page that pops-up, click on the Part marking lookup.  Click Search by Marking on the part, then enter 3721 in the Search phrase box, then Lookup. 

What is returned is a list of devices, however, in this case, no match is found.  I had at first thought this to be a TPS7A3721, however these are only in a WSON (no leads) package, not SOIC. 

So, after all that, we're still no closer to finding out what this device truly is!  Let me research this some more. 

Where did this device come from?  Was it on a circuit board, and if so, what are the marking on the board?  Who is the manufacturer?

And finally, there is a possibility it is a counterfeit device. 

More to follow . . .

~Leonard  

Hi Leonard:
Thank you for your reply!
This chip I removed from Concept gate driver, 1SD210F2. It is a 8 pin SOIC chip and serves as a comparator, I believe
I want to know this information for reason below:
We had an old driver, which only this chip is destroyed during debugging. After I remove this from the board, the driver works properly and the only shortage is, the de-sat protection will be disabled, as missing the comparator. I contact Concept for repair service, and they told me they don't provide such service. I don't want to waste 300 dollars for this reason, and try to replace the chip by myself.
I don't know whether this is related to some secrete or not. If it is a normal commercial product and I can buy some for repair, that will be great.
The only thing I want to complain in this story, is the Concept. They only want you buy new ones, instead of spending 10 dollar to repair it!!! Very tricky!
Anyway, thank you for your help.
Best,
Luxing

This is the product, correct?: http://www.mouser.com/ds/2/328/1SD210F2-FZ750R65KE3-612511.pdf .  Technical manual is here: https://gate-driver.power.com/sites/default/files/product_document/application_manual/1SD210F2_Manual.pdf , but no schematic, and yes, there is a comparator for VCE monitoring.

You may have to go to Concept website, technical support, ask for a schematic.

Hello Luxing,

When I do an internal search on TI device marking codes one possibility that I arrive upon is the TLE2037MD. It is a precision operational amplifier available in the 8-pin (D) SOIC package. There are a number of analog circuits in the IGBT driver circuit tha appear to be using operational amplifiers.

You can find the datasheet here:

 Regards, Thomas

Precision Amplifiers Applications Engineering