Converting PPM (Parts Per Million) to Number of Bits (LSBs) for INL Specifications

Updated Jan 10, 2023

I looked at the specifications for my board online to find out what the INL was. I was expecting to see a value given in LSBs (least significant bits) but I see that the INL is given in PPM (parts per million). How can I convert this PPM value to LSBs?

To convert from PPM to LSBs you divide 1M by the # of LSBs. 

For example: a 16 bit device has a specification of 10ppm INL

To convert this:
1M/(2^16) = 15.3ppm/LSB
10/15.3 = 0.654

The INL for this board is 0.654 LSBs

To go straight from PPM to voltage you would do: 10ppms of 1V = 10uVor Integrated NonLinearity. This is an accuracy specification for ADCs

Additional Information

NOTE: INL stands for Integrated NonLinearity. This is an accuracy specification for ADCs