Sense amplifier driving circuit employing current mirror for

Abstract

A sense amplifier driving circuit for controlling sense amplifiers of high density semiconductor memory device by turning-on/off a driving transistor connected between an external voltage Vcc terminal and a ground voltage Vss terminal, comprises a bias circuit including a MOS transistor being connected to the driving MOS transistor to form a current mirror circuit therewith which is controlled by a sense amplifier enable clock and a constant current source having a MOS transistor with a bias voltage of an intermediate level between Vcc and Vss being applied to its gate terminal. The bias circuit is connected to the gate terminal of the driving transistor to control the gate voltage of the driving transistor, thereby reducing the peak current of a sense amplifier driving signal. Further, the driving signals are generated in the waveform having a linear dual slope, resulting in a decrease in power-noise. The bias circuit is connected to a clamping circuit having a comparator circuit to clamp the active restore voltage of the sense amplifier driving circuit, so that the active restore voltage can be maintained at the level of an internal voltage (approximately 4V), thereby preventing the distortion of the characteristics of the cell device and eliminating the necessity of additional standby current by enabling the sense amplifier only for the active restore operation. Further, the sense amplifier driving circuit comprises a constant circuit including two or more current mirror circuits which are sequentially activated, whereby the sense amplifier driving signals are made to have stable linear dual slopes.