Most line drivers with low differential output impedance will also have inherently low common-mode output impedances, so the low impedance arms of the bridge are almost always at the driver.

Equipment designers can minimize the effects of these mismatches or "unbalances" through judicious choices of input and output stage circuit topologies and common-mode impedances.

Used the switched capacitor Common Mode Feedback circuit(CMFB) in main amplifier to achieve a large output voltage swing and decrease the static power consumption at the same time.