Memory circuit improved in electrical characteristics

Abstract

A constant current source is connected in series to a current source circuit including a MOS transistor which is used as a current source for a differential output amplifier circuit, an emitter follower circuit or a source follower circuit used with a semiconductor integrated circuit. In a multiplex circuit, an input signal is inputted to each of base terminals of a plurality of bipolar transistors. When one input signal is selected, the bipolar transistor corresponding to the selected input signal is made to be operable with an input signal from a signal input terminal by a control circuit. The bipolar transistors corresponding to the non-selection input signals are turned OFF irrespective of potential levels of the individual input signals by current drawing circuits. There is also disclosed a semiconductor memory circuit having a plurality of memory cells, a memory cell selection scheme and a sense amplifier for amplifying data outputted from the selected memory cell, in which a constant current circuit is provided in series connection to the sense amplifier to enhance the performance characteristics of the memory circuit. Also, a plural memory array scheme is disclosed which employs multiplexing techniques connected to presense amplifier circuits of the respective memory arrays.