ADE7756: Maximum CF frequency

Document created by analog-archivist Employee on Feb 23, 2016
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I am designing a watthour meter with ADE7756. Max input voltage is 245 v and
current is 65A. The CF is to be 1600imp/kwh.
I have calculated that CFDIV should be decimal 789. I this correct ? APGAIN=0

 

The maximum CF frequency from the ADE7756 is 5.56kHz.
If you consider that your maximum inputs represent 50% of each analog full
scale of the ADE7756, then the frequency at these level would be 5.56/4=1.39kHz.
On the other hand, based on the voltage and current levels, the expected CF
frequency is: 245x65x1600/3600/1000=7.08Hz. The CF divider should then be
around  1390/7.08=196d.
Anyway, I recommend that you follow the calibration procedure on page 24 of the
ADE7756 datasheet.

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