in semiconductor circuits , and particularly in memories , it is often desirable to use bipolar transistors for speed together with mos elements . however , although the bipolar transistors are useful for speed considerations , they undesirably significantly increase the power consumption of the overall circuit . accordingly , to reduce power consumption , a bipolar / mosfet arrangement is provided wherein mosfets are used as current sources to supply operation currents to the bipolar transistors only during the periods of their operation . thus , a semiconductor integrated circuit device is achieved featuring a high operation speed yet consuming reduced amounts of electric power . additionally , power consumption can be further reduced by providing a time serial operation for actuation of the mosfets in different peripheral circuits for a memory array .