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ADE7753 - Voltage sense inputs

Question asked by jeremy-insset on Jul 16, 2013
Latest reply on May 6, 2015 by hmani

Hello everybody,

 

I am Jérémy and I am interested in learning how to use the ADE7753. I printed few documents from analog devices website:

  1. Single-Phase Multifunction Metering IC with di/dt Sensor Interface
  2. EVAL-ADE7753EB manual
  3. AN-564
  4. AN-639
  5. Solid State Electricity Metrology

 

My questions are related with the voltage sense inputs. I understand that between the Phase line and the V2P pin we have to perform 2 operations. The first operation is to downsized the signal (230V-50Hz, here) to an acceptable level (+/-0.5 Vmax.). The second operation is to add an anti-aliasing filter to provide a "clean" signal to V2P. So, according to page 5 of 20 from the document 2:

 

  1. R53, R54 and R56 are used to perform the operation 1 but where is the resistor to perform the anti-aliasing filter with C53 ? I am sorry if the question is "silly" but I have a problem to understand this.
  2. Let's assume that with the R-C filter, R = 1kohms this would means that fc = 4823 Hz, why this value ? Our signal is 50Hz (60Hz max.)
  3. Why an anti-aliasing filter (R57 and C54) is connected to V2N and is it normal and safe to connect AGND to Neutral (see JP10) and why ?

 

Thank you very much, sincerely.

 

Jérémy

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