The LM43603 is designed to operate from an input voltage supply range between 3.5 V and 36 V. This input supply should be well regulated and able to withstand maximum input current and maintain a stable voltage. The resistance of the input supply rail should be low enough that an input current transient does not cause a high enough drop at the LM43603 supply voltage that can cause a false UVLO fault triggering and system reset.

If the input supply is located more than a few inches from the LM43603 additional bulk capacitance may be required in addition to the ceramic bypass capacitors. The amount of bulk capacitance is not critical, but a 47 µF or 100 µF electrolytic capacitor is a typical choice.