LM5085: Buck Controller duty cycle and output current queries

Hi,

Our Requirements are,

Vin Range: 12V to 48V
Vout: 12V

Iout: 5A

Questions:

1) If we are giving 12V input, with 100% duty cycle, we will get 12V output? Or some tolerance in output will be there?

2) For 100% duty cycle, what maximum swithcing frequency it supports?

Thank you