Isolation amplifiers are used to sense and isolate voltages and are typically used to measure phase currents (with shunt resistors) or DC-link voltages in three phase frequency converter power applications.
The maximum current is limited by the input voltage range and power dissipation in the shunt resistor. With 200mV input voltage range, currents of 150A are easily implemented. However, if state of the art shunt resistors and thermal management is applied, currents of 500A are within reach. The bandwidth/response time is in the range of 1.6 s for analog parts and 20MHz for sigma-delta outputs which is fast enough for fault detection and protection in most applications.