What is the meaning of LSB in representation of AD conversion errors ?

Answer

AD conversion errors are measured in a unit called the LSB (least significant bit). 
If the conversion error of an AD converter is specified as ±2 LSB, conversion results may include an error of ±2 digital values. For example, if an 8-bit AD converter has 0.0V to 5.0V conversion range and a conversion error of ±2 LSB, the AD conversion range of a 2.5V input, may vary in a range of 0x7e to 0x82. If the AD converter is error-free, the conversion result will be 0x80.

(NO.EA9901701 2011/11/01)