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hardware issue

Category: Hardware
Product Number: ade7753

Hello everyone,
I tried making a circuit with the ADE7753 and encountered some issues that damaged my ADE. Initially, I combined the voltage divider circuit and the current measurement CT circuit with the power supply circuit. When I powered on without connecting AGND between the power supply circuit and the ADE circuit, there were no apparent issues. However, when I connected AGND to the ADE circuit, resistors R2, R5, R6, R7, and FB1 in the ADE circuit all burned out along with my ADE. Upon checking, I realized that I used 22pF capacitors (C8 and C9) instead of 100nF, but I don't think that was the cause. I didn't find significant differences in my schematic compared to the proposed design. Can someone help me identify the issue
Thank you!
This is my schematic

  • I need to see how you connect to the micro. 

    Do you have the board connected to a laptop or PC? Do you have isolation? 

    Are you sure the voltage divider components are the correct value? 

    Everything in the schematic seems ok. 

    please don't list in multiple locations on ezone. 

    Dave

  • I'm sorry for asking twice, I think I provided too little information earlier so I want to add more details to my previous question.

    I didn't connect my circuit to a laptop or PC, just simply powered the ADE board, connected neutral to ADE's AGND, and connected the two voltage channels V2P, V2N and current channels V1P, V1N. Then, my circuit burned out.

    Regarding the voltage divider resistors, I checked and ensured their values are correct. I measured the voltage between V2P and V2N and found it to be only about 0.22V, which is well within the permissible range.

    I also checked the neutral and phase wires to rule out the possibility of confusion between the two wires. It's possible that the issue was caused by the components or the ADE itself.

  • It is not the ADE something about the components or setup that is not shown in the schematic. 

    Did the part die with voltage only and no load? 

    Did it die with load? Is the voltage from the CT to high? If the burden is not connected to the CT, the voltage from the CT can get quite high and damage a part. 

  • Indeed, my circuit burned out when I simply connected the ADE board to the power supply board without any load operating, so there was no voltage present at the CT

  • Hi Dave,

    Do you know what could have caused the issue in my case? Or do you think there are specific things I should check to get to the root of the problem?

  • You have a 5v dc converter that I am guessing supplies power to the board. I can see you have a AVDD and DVDD net and a 5v_out, but I can't see how they is connect. 

    You need to remove the ADE7753, replace the bad components power the board minus the ADE7753 and debug the issue. Something is wrong with the  components, pcb or the setup. The schematic appears ok but pieces are missing so I can't confirm and is the pcb correct to the schematic? Start checking traces with an ohmmeter to see if there is an issue. 

    Dave

  • Thank you, Dave. I will try checking again as you suggested. Here is how I connected the two boards together. There may not be any issues with DVDD, AVDD, and 5V because I powered the board and everything seemed fine. The problem only occurred when I connected the voltage measurement channels to the board.

  • Hi Dave, I have another question I'd like to ask you. If I connect GND and AGND, and then connect AGND to neutral, wouldn't I be short-circuiting PS1 and B1?