I have tested the LTC3118 by a single power supply from 3.6V to 7.2V, the output voltage is 5V. I have used the Vin1 pin as the voltage source for the converter. My question is that where the unused Vin2 pin and the Run2 pin are connected to. I have connected the Vin2 to GND and the Run2 to the Run1(=Vin1), is it no problem?
If a second input source Vin2 is not used , VIN2 and RUN2 pin can be grounded. Connecting RUN2 to RUN1 will not create any problem however it might always enable few of the internal circuitries(such as RUN2 comparator) of the part. This will make it less efficient.
If dual input source is not required for the application, LTC3119 could be a better part for the specification in terms of efficiency, power loss, adjustable switching frequency etc.