公开(公告)号：JPH02158998A

公开(公告)日：1990-06-19

申请号：JP27050089

申请日：1989-10-19

Applicant: IBM

Inventor： SHIRUBEEN RUFUORESUTEIE ,  DOMINIIKU OME

IPC: G11C7/06 ,  G11C11/416

Abstract: PURPOSE: To attain operation in a constant state by providing common base amplifier means connected to a reference voltage generator. CONSTITUTION: By selecting proper values of resistors R1-R8 and current sources IB1-IB6, a voltage gain becomes maximum at the time of high-speed operation. The saturation of a first differential amplifier stage of transistors T3, T4 is avoided by adjusting a voltage between both ends of resistors R3, R4 to be less than the saturation. The saturation of a second differential amplifier stage of transistors T5, T6 is prevented by means of a reference voltage generating circuit 13. Dot coupled capacitance received by a first stage is sharply decreased by a second stage or a final stage. The maximum voltage applied on the common base of transistors T9, T10 is VREF, the minimum voltage applied on the collector electrodes when they are turned off is VH-2VBE and thus 0.5VBE is used for preventing the saturation of transistors T9, T10. Consequently, the output swing of the final stage is restricted to a value lower by 2VBE than VH and a high swing signal is supplied to a BICMOS circuit connected to a terminal 18. Thus, the circuit is operated in a constant state.