The differential amplifier has the ability to suppress signals common to the two inputs.
CMRR is an indicator of the ability.
As energy conservation advances, transformers and motors are becoming more efficient. Improvement of efficiency requires reduction of loss (iron loss and copper loss). The parts used in the devices are operating at high frequency. Therefore, we should evaluate the copper wire used in the devices in a state close to the actual condition, that is, at high frequency.
In this document, we introduce two technologies, bias stabilization technology and active input impedance to achieve low noise characteristics employed in SA-230F5 and SA-430F5.