Please tell me how to handle the unused B pin(1B1,1B2...).
This thread has been locked.
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.
They can be left floating; see [FAQ] Frequently Asked Questions about signal switches and multiplexers.
Clemens is correct - unused analog I/O pins can be left floating. However in higher speed applications if you want to reduce the chance of reflections caused by the IC itself it is recommended to terminate unused pins with 50 Ohm resistors to ground.
If you have any other questions please let me know!