In a MOS transistor circuit (comprising a pair of current mirror circuits, each comprising: first and second MOS transistors having their gate electrodes connected together; third and fourth MOS transistors respectively connected in series with the first and second transistors the third and the fourth MOS transistors of the pair of current mirror circuits receiving a pair of complementary signals at their gate electrodes; and the nodes between the second and the fourth MOS transistors forming output nodes of the current mirror circuits), a pair of capacitors each coupling the output of one current mirror circuit to the gate electrodes of the first and the second MOS transistors of the other current mirror circuit. This provides positive feedback. The change in the outputs responsive to change in the inputs is thereby accelerated.