The AMC3301 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 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 of the AMC3301 in a solar inverter where the phase current is measured on the grid-side of an LCL filter. Although the system offers a supply for the high-side gate driver, there is a large common-mode voltage between the gate driver supply ground reference and the shunt resistor on the other side of the LCL filter. Therefore, the gate driver supply is not suitable for powering the high-side of an isolated amplifier that measures the voltage across the shunt. The integrated isolated power supply of the AMC3301 solves that problem and enables current sensing at locations that is optimal for the system.

The diagram also shows the AMC3330 being used for sensing the AC output voltage.

Figure 8-1 The AMC3301 in a Solar Inverter Application