A related question is a question created from another question. When the related question is created, it will be automatically linked to the original question.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Naizeng is correct. B denotes the accuracy grade where it has better initial accuracy and temperature drift. U denotes the SO-8 package. See the screenshot below taken from the datasheet: