8.2.1.1 Design Requirements

Figure 50 shows a diagram of the AMC1204 in a typical frequency inverter. When the inverter stage is part of a motor drive system, measurement of the motor phase current is done via the shunt resistors (R_SHUNT). Depending on the system design, either all three or only two phase currents are sensed.

In this example, an additional AMC1204 is used for isolated sensing of the DC link voltage. This high DC link voltage is reduced using a high-impedance resistive divider before being sensed by the AMC1204 across a smaller resistor. It is important to consider that the value of the resistor in the voltage divider can potentially degrade the performance of the measurement. Such phenomenon is described in the Isolated Voltage Sensing section.