AnsweredAssumed Answered

ADE7878 calibration without an accurate source

Question asked by edmont on Nov 18, 2015
Latest reply on Nov 23, 2015 by hmani

I've read a lot about calibration in this forum and in the data sheets and application notes. For example, the AN-1076 proposes two methods: accurate source method and reference meter method. But it's funny because if you choose the second one, it states:

 

To calibrate the current and voltage rms, use the accurate source method. See the Current and Voltage RMS Calibration section for additional information.

 

So, at the end, there is only a suitable method, according to the application note.

 

What I'd like to do is to use a reference meter for all the process, selecting three points:

  • Zero load, with no voltage or current applied to the circuit.
  • Known resistive load, using the mains power as power source, with some PF=1 loads.
  • Known inductive load, using the mains power as power source, with some PF<1 loads.

 

I guess this method could characterize the chip + circuit deviations in terms of gain and offset, but I have doubts on how to save that information in the calibration registers.

 

For example, is the zero load Vrms reading somehow related to the xVRMSOS register value?

Outcomes