TIDUF25 june 2023 ADS131M08 , MSPM0G1507
Except being used for electricity meters, this standalone ADC architecture applies also for power quality analyzers and power quality meters and EV chargers or wallboxes. This end equipment is used to monitor and control power quality by measuring certain power quality parameters, such as voltage harmonics, current harmonics, supply voltage dips, supply voltage swells, and other parameters as well. For all equipment, a lot of computation is required for calculating the power quality parameters. Also, accuracy is important to be able to meet the accuracy requirements for the different power quality parameters. The requirement for high accuracy and computation power is something well supported by having a standalone ADC and separate host MCU or processor, as is done in this design.
A couple of the parameters commonly measured by power quality meters and power quality analyzers are voltage and current harmonics. For the most accurate harmonic calculations, implement coherent sampling. One way of implementing coherent sampling is to vary the sampling clock based on the Mains frequency. The standalone ADC in this design has the ability to take in a varying clock so the ADC can support coherent sampling. Although the clock to the standalone ADC in this design can be varied, this design cannot support coherent sampling because the sampling clock from the host MCU to the standalone ADC cannot be varied with the proper resolution.