AMC23C10: Zero-Cross detection circuit detecting peak instead of zero volts

Here are some screenshots:

I'm detecting falling edges only every 20ms for 50Hz AC

Here's the OUT2 compared to the AMC INP/INN:

Here's AMC INP/INN compared to the AC:

Here's the OUT2 compared to the AC:

Connecting Neutral to GND1 blows the circuit, the AMC23C10 high side is powered through an isolated SMPS.

Hi LA,

Which part of the circuit blows?

The initial schematic is incomplete, so here’s a more detailed version that includes the SMPS internals. I connected AC1 to GND1/INN, which caused the fuse to blow along with the bridge rectifier.