Can the MODE pin on the MAXM17623 / MAXM17624 be driven high or must it be left floating/unconnected to select PFM mode?

The MODE pin can be driven high as long as it doesn't exceed its absolute maximum value of  (VIN + 0.3V) as shown on page 2 of the datasheet.

Tags: MAXM17623AMB+T KA-05463 uSLIC power modules