Hi Team,
Can you help below:
A customer is using TIDM-SINGLEPHASEMETER and I have a question about the implementation of the Analog Front End (AFE) that is shown on page 5 of slaa517f.pdf.
They are trying to measure the power consumed on 240VAC lines, in conjunction with a switching mode power supply (SMPS) instead of the provided capacitive power supply. The issue we have is that the V- connection needs to be connected to the -120VAC (L2) line through a voltage divider, for which a circuit is not provided in the reference design. Also, the V- signal can not be directly connected to the ground of the MSP430, which is connected to the low-side of the SMPS, which is tied to Earth ground, as that would be completely unsafe. they have prototyped the attached AFE, but have had some issues with the readings. The MSP430 SDC impedance is modeled as a resistance using the values provided to the datasheet (200k per channel, 400k between the channels).
Can you please check and let me know if nits the right approach?
Thank you
Regards,
Marvin
