In the document, the MSP430F6736 microcontroller, which consists of a measurement system on-chip (SoC), belonging to the MSP430F67xxx family is used. The same device can also be used in two- or three-phase systems.
The microcontroller features a 25 MHz CPU, and incorporates up to 3 sigma-delta 24-bit analog-to-digital converters.
The sigma-delta inputs operate independently providing a 24-bit resolution output and can be grouped together to obtain simultaneous voltage and current samplings from the same release.
In Figure 1 we have the meter diagram that can be used with voltages of 230 V, 120 V in 50 Hz or 60 Hz.

In the Texas Instruments documentation, the reader will find the details of each stage of the circuit with the values ??of the components.
In Figure 2 we have a suggestion of direct power to the circuit.

The program for implementing the meter can also be found in the same documentation.
2005