If you think that the chip may be an accelerometer, I assume that you have figured that out from the PCB functionality, there are not that many manufacturers of those devices. A quick check of their web sites should allow you to find if it is, the data sheets normally have the code that helps to identify them in the packaging information. You may also need to include devices with a gyro and sometimes a magnetometer as well, although I doubt it, considering the physical size of the chip.
If the PCB is an OEM product, then things can get much more difficult. There is a list here of the key players.
https://www.marketsandmarkets.com/Market-Reports/3d-sensors-market-248537071.htmlIf the company is Asian based, then it may be difficult to get data.
If the chip is not a 3D sensor, then again, it may be possible to narrow down its purpose from knowing what the functionality of the board is, particularly if other chips can be identified. You may have to reverse engineer the PCB to get a rough schematic.
Cheers,
Richard
