I'm working on circuit to measure power factor for audio (in the frequency range from ~20-100hz).
The issue I'm having is the output of the MAX919esa+ is not in phase with each other and causes these double pulses when I XOR them.
In the scope capture,
yellow trace: output of XOR (U8)
blue trace: output of MAX919 pin 6 (U6) - voltage measurement
green trace: output of MAX919 pin 6 (U5) - current measurement
You can see that the output of the MAX919s do not line up. The position of the blue trace will shift left/right as I increase/decrease voltage as well.
Circuit setup:
J1 & J2 is connected to a current transformer (CR8410-1000). J3 is connected to the output of a half bridge amplifier, J4 is left unconnected as the amplifier is common ground with the circuit. Speaker load is also connected to the amplifier.
Schematic attached below. Note, U7 is not installed. I'm also using one 2.5V reference for both MAX919 as there was a few mV of difference between the two.
