Thanks for your inquiry.
According to BMA253 datasheet, the first character on the second row of the laser marking must be letter "U". For example, the valid laser marking for BMA253 will be "SYN US" or "272 UB", etc. for example.
The laser marking of "2BA 8A" is actually BMA250 10-bit accelerometer with technical reference code of 0 273 141 121". BMA250 has been discontinued a few years ago. I am not sure where you purchased these parts.
Again, please always purchase Bosch MEMS sensors through authorized distributors or sales representatives at https://www.bosch-sensortec.com/about-us/contact/our-distributors-and-sales-representatives/.
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