The AMC3301-Q1 is ideally suited for shunt-based current sensing applications where accurate current monitoring is required in the presence of high common-mode voltages. The AMC3301-Q1 integrates an isolated power supply for the high-voltage side and therefore makes the device particularly easy to use in applications that do not have a high-side supply readily available or where a high-side supply is referenced to a different ground potential than the signal to be measured.

Figure 8-1 shows a simplified schematic using the AMC3301-Q1 to measure the output current of a PFC stage of an onboard charger (OBC). At this location in the system, there is no supply readily available for powering the high-side of the isolated amplifier. The integrated isolated power supply solves this problem and, together with its bipolar input voltage range, makes the AMC3301-Q1 ideally suited for bidirectional current sensing. In this example, the AC line-voltage is sensed by the AMC3330-Q1 on the grid-side where there is also no suitable supply available for powering the high-side of the isolated amplifier. The integrated power supply, high input impedance, and bipolar input voltage range of the AMC3330-Q1 make the device ideally suited for AC voltage-sensing applications.

Figure 8-1 The AMC3301-Q1 in an OBC Application