PWR#/I2C_SDA can be used as either PWR# or I2C_SDA but not as both in 28-pin QFN Package. If EEPROM is connected then the pin will act as I2C_SDA, it will not switch to PWR# mode (as it does in 48-pin TQFP package).
If EEPROM is not being used, PWR# is an active LOW pin (LOW when activated), which needs an external pull-up resistor.
TEST pin can be used for Test Mode by driving it HIGH. For Normal operation it is recommended to drive this pin LOW.
Also, make sure to connect PWR# to VCCD/+5V with 100kohm resistors, OVR# to the same power with 10Kohm. Because PWR# is open drain output and OVR# is open drain input.
For more details on test pin, please refer: