SEMICONDUCTOR DEVICE

PURPOSE:To quicken the falling of an output of an emitter follower output stage without incurring increase in power consumption by increasing a current of a current source of an emitter follower whose output falls down and decreasing a current of a current source of an emitter follower whose output rises. CONSTITUTION:When an output X changes from H to L and an output Y changes from L to H, a current in a path comprising diodes D2, D4 and a resistor R6 is increased and a current in a path comprising diodes D1, D3 and a resistor R7 is decreased, a transistor(TR) T6 is conductive deeper, then the current of the current source is increased and a TR T7 is less conductive, then the current of the current source is decreased. Thus, the falling of the output X is steep and the output Y is promoted. When the output X changes from L to H and the output Y changes from H to L, the current in the path comprising diodes D2, D4 and the resistor R6 is decreased and the current in the path comprising diodes D1, D3 and the resistor R7 is increased, the TR T7 is conductive deeper to make the falling of the output Y steep. Moreover, the TR T6 is less conductive to promote the rising of the output X. Thus, the power consumption is reduced more than the case with increasing currents of both the current sources.