How to bypass current sensor (ACS712) default 2.5V voltage output in buck/boost converter PCB
It seems like there is a fundamental conceptual disconnect here. The ACS712 output is offset to mid-rail to facilitate reading voltage when the current can be either positivist or negative. The ACS product literature calls this &quot;bipolar.&quot; Some ACS current sensors are unipolar (although they may be offset slightly above ground anyway).
It seems like your best bet to fix up your circuit will be to remove the 2.5V offset at the op-amp. Please note that the ACS devices are &quot;ratiometric&quot; meaning that the offset will be very close to mid-rail (VCC/2). So rather than use a precision 2.5V reference to generate that offset at your op-amp, you would want to use a voltage divider from the same VCC that powers the ACS712, if possible.