The INAx191 uses a capacitively coupled amplifier on the front end. Therefore, dc common-mode voltages are blocked from downstream circuits, resulting in very high common-mode rejection. The common-mode rejection of the INAx191 is 150 dB (typical). The ability to reject changes in the DC common-mode voltage allows the INAx191 to monitor both high- and low-voltage rail currents with very little change in the offset voltage.