Do not leave the inputs of the AMC1301-Q1 unconnected (floating) when the device is powered up. If the device inputs are left floating, the input bias current can possibly drive the inputs to a positive value that exceeds the operating common-mode input voltage, thus causing the device to output the fail-safe voltage as described in the Analog Output section.

Connect the high-side ground (GND1) to INN, either by a hard short or through a resistive path. A DC current path between INN and GND1 is required to define the input common-mode voltage. Take care not to exceed the input common-mode range as specified in the Recommended Operating Conditions table. For best accuracy, route the ground connection as a separate trace that connects directly to the shunt resistor rather than shorting GND1 to INN directly at the input to the device. See the Layout section for more details.