The EP pin should be connected to GND for the TDFN package.
MAX1605
Production
The MAX1605 boost converter contains a 0.5A internal switch in a tiny 6-pin SOT23 package. The IC operates from a +2.4V to +5.5V supply voltage, but can...
Datasheet
MAX1605 on Analog.com
The EP pin should be connected to GND for the TDFN package.