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ADE7763 Isolated Voltage Measurement

Question asked by David-DJRTech on Feb 12, 2013
Latest reply on Feb 20, 2013 by hmani

I am designing a single phase power measurement circuit using the ADE7763 for interfacing to a controller circuit. I need to achieve 3750V reinforced insulation between ADE7763 power measurement circuit and ucontroller. Rather than achieving insulation on the digital side of the ADE7763, I was wondering if it is feasible to achieve it on the analog side. For current measurement, this can be achieved using a suitably rated current transformer. However, for the voltage measurement, I would need to use a pair of say 490k resistors from each of the Phase and Neutral lines (refer circuit sketch). Since the voltage measuring input of the ADE7763 is now subject to common mode voltage between ground and neutral, I am wondering what the common mode rejection performance of the ADE7763 input stage is, however no such information is provided in the ADE7763 datasheet? Does this mean that I should not be making voltage measurements this way? Any advice on this matter would be greatly appreciated.

 

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