AFE3010: Unable to get the proper waveform at OUT pin and device is not tripping.

Hey Haresh,

So you line voltage is 50 Hz?

What is the desired trip time for 30mA leakage?

What does V_OUT look like when there is no leakage current? Is device passing self test?

Would you mind sending a schematic? You can message me privately too if that works.

To get the slowest trip time (~150 ms), you want 30mArms to yield a waveform on OUT that is centered at 2.5V and peaks at ~ 2.75V and troughs at 2.25V and has the same frequency as the line. 

An OUT voltage that has a primary frequency component of 150 kHz sounds like oscillation. You may want to increase C3, which will help stabilize the loading of the CT impedance.

Sincerely,

Peter

You could also try increasing R6 and increasing R7, as opposed to just decreasing R7 to reduce gain. The drawback to increasing R6 is that you will increase gain non-linearity over temperature and you will reduce the amplification of the Neutral-to-ground pulse seen in Figure 18. Although, CTs can vary significantly in impedance and you will want to validate your system.

I recommend increasing R6 to 100Ω or 150Ω and then tune R7 to get the threshold to 30 mArms. Increase C3 if signal chain is still oscillating. Once you have the gain set to trip at 30 mArms, then check the N-G detection capability as per Figure 16 (if N-G is required for your system).

Sincerely,

Peter