the sample rate of ADE7751

Hi,

I'll be moving this thread to its proper community https://ez.analog.com/energy-metering/. Someone here may be able to assist you.

Thanks,

Jellenie

Hi Lynne, 

The ADE7751 is a metering IC for AC energy. 

Current and voltage channel sample rate of the Sigma delta ADC is clk/4 or 3.579Mhz/4 or 894750Khz. 

The Anti-alias and the internal Sync filter determine the measurement bandwidth 14Khz. 

Voltage channel  is multiplied by the current channel  internally accumulated and a digital to Freq conversion is done to create a pulse output proportional to AC Energy. 

This is not an ADC. You have no way to read ADC samples. All you get is a CF (calibration Frequency). 

Can you explain what you are trying to do? 

Dave

Thanks  Jellenie，I'll see it.

Hi Dave,

Thanks for your reply. I only know that the sampling rate is 4.8Khz and the metering IC is the ADE7751. I wanna know that how can I calculate the sampling rate. Could you help me out and tell me the formula? I will be deeply grateful.

Lynne

Hi Lynne, 

I am still not sure what you are asking for. The adc sample rate is based on the crystal input /4 3.579Mhz/4 or 894750Khz. 

Can you show me a schematic of what you are trying to do with input signals and output signals?and where does the 4.8Khz sample rate come from?

Dave

Hi Dave,

Thank you for your reply. I'm sorry that I don't have the schematic of what I am trying to do with input signals and output signals. My customer gave me a picture and asked me how could he get 4.8khz. I only know that the metering IC is ADE7751 and I don't have any information about this. 

Lynne

Hi Lynne, 

The important information is the 3200imp/Kwh. This is the meter constant and used to calibrate the meter. In this case I am guessing the ADC used has a sampling rate of 4.8Khz. The ADE7751 samples at the crystal /4 or 894750Khz the sync output bandwith is 14Khz. The ADE7751 has a higher sample rate than 4.8Khz so you will be able to measure the same information. 

You should not focus on the 4.8Khz so much. I think this number is indicating how may harmonics the meter can measure. The ADE7751 can measure the required harmonics with a 14khz bandwidth. 

This will help you design a meter with the ADE7751 

https://www.analog.com/media/en/technical-documentation/application-notes/AN-574.pdf

based on your photo these are you values.

V= 230V

I=5 amps nominal (IB) and (40) Max

50Hz 

3200imp/KWH

Dave

Hi Dave,

Thanks for your reply.I will refer to the link you sent me.And thank you so much for your assistance.

Lynne