This device is designed to operate over a recommended input voltage supply range of 4.5 V to 35 V. The input supply must be well regulated. If the input supply is located far from the LM3485 EVM and needs a long power supply cable to connect, an additional bulk capacitor may be required. An electrolytic capacitor with a value of
47 µF can be used typically.

As mentioned in Current Limit Operation, at higher input voltages (> 28 V) an increased negative SW transient spike at the switch node can lead to an increase in the current limit threshold due to the formation of the parasitic NPN connection between the ISENSE pin, the internal substrate and the ADJ pin . To avoid this issue, a Schottky catch diode with lower forward voltage drop must be used. In addition to that, a resistor must be placed between the ISENSE pin and the external switch node. A resistor value in the range of 220 Ω to 600 Ω is recommended.