In ADm7154 datasheet, the EN input, Logic HIGH is specified from 1.13 to 1.31V.
We intend to pull up this pin to voltage input, 5V5.
Is this correct?
From the figure 49 on datasheet (page 17) the given values from page 4 (parameter section) for low and high get clear. Defined are the threshold voltages for disabling and enabling the part, not the max/min levels of a DC signal at Enable pin. if you connect EN with VIN (like your 5.5V) the part starts automatically with VIN.