JAJSR80 September 2023 AMC131M01
PRODUCTION DATA
Figure 9-5 illustrates phase A of a three-phase energy meter. The other AMC131M01 devices that monitor phases B and C are connected in a similar way. The phase A current, ISHUNT, is sensed with a shunt resistor (RSHUNT) using channel 0 of the ADC (AIN0N, AIN0P). One terminal of the shunt becomes the isolated ground ISO_GND of the circuit and is connected to the ground pin HGND (pin 5) of the isolated side of the AMC131M01.
The selection of the shunt resistor value is made based on the manufacturer and current range required for energy measurements.
The measurement of the mains voltage is not shown in Figure 9-5. This voltage measurement is typically implemented by sensing each individual phase voltage with a resistor divider connected to a non-isolated multichannel ADC. This multichannel ADC can be implemented as a discrete component, or using the onboard ADC of the MCU if available.
In this design, the AMC131M01 interacts with an MCU in the following manner: