2855 - Power Manager II: Do I need to connect a 100 ohm series resistor between monitored voltages and VMON pins on the POWR1220AT8 device?
No, you can connect the VMON pins directly to monitored voltages which are between 0 and 5.9V.
Some of the Lattice evaluation board schematics do include a resistor between the monitored voltage and the VMON pins. This is typically only used with the differential voltage monitoring, which routes both the VMON and VMONGS (voltage monitor ground sense) pins to the supply and ground sense pins at monitored IC or DC-DC converter. In this case the 100 ohm resistor is placed on both the VMON trace and the VMONGS trace. These resistors are optional and board or design dependent.
For voltage monitors which connect the VMONGS pin to the board ground, no resistors are needed.