How can the monitoring accuracy and EMC of an intelligent low-voltage monitoring unit be balanced?

Balancing monitoring accuracy and EMC requires a low-noise design and appropriate filtering.

Low-noise components were selected: AD8629 operational amplifier and ADS8568 ADC.

Filtering design: A second-order active filter was used, with the cutoff frequency slightly higher than the signal bandwidth.

PCB layout: The sampling loop area was minimized, and differential routing was employed.

Power supply decoupling: A 10μF + 100nF capacitor was placed near each power supply pin.

This design achieves a monitoring accuracy of 0.5 class while meeting the IEC 61000-4-8 power frequency magnetic field immunity test requirements.