Abstract: Disclosed herein is an ATD circuit of the present invention. In order to generate a stable ATD pulse, a pulse width amplifier circuit is provided between a first circuit means and a second circuit means. The first circuit means outputs a first output signal having a first pulse width in response to a change in external address signal and outputs, when the external address signal is brought to a first sawtooth signal, a second sawtooth output signal having a peak value smaller than that of the first sawtooth signal. The second circuit means inputs therein the signal outputted from the pulse width amplifier circuit and waveform-shapes the output signal so as to output an ATD signal therefrom. The pulse width amplifier circuit amplifies a pulse width of the signal outputted from the first circuit means.

Abstract: A sense circuit for a DRAM circuit in which small potential difference between bit lines and is produced when the memory cell in the memory cell array is connected to one of the bit lines. The sense circuit starts sensing and amplifying when the sense starting signal changes to "L" level. An inverter provides a sense activating signal of "H" level to an NMOS device, while another inverter provides a sense activating signal of "L" level to a PMOS device. Sense amplifiers 33 are then activated and the potential difference between the bit lines and is amplified. Since the "L" level of the sense activating signal that is generated by the inverter is set to a value midway between a first power potential VSS and a second power potential VCC, the conductive resistance of the PMOS device is higher than that of a conventional circuit supplied with the first power potential VSS. Consequently, the voltage drop due to the PMOS device increases and power noise is reduced.

Abstract: In an ATD circuit, a pulse width amplifier circuit is provided between a first circuit means and a second circuit means. The first circuit means generates a first output signal having a first pulse width in response to a change in external address signal and generates, when the external address signal becomes a first sawtooth signal, a second sawtooth output signal having a peak value smaller than that of the first sawtooth signal. The second circuit means receives therein the signal generated by the pulse width amplifier circuit and waveform-shapes the output signal so as to provide an ATD signal therefrom. The pulse width amplifier circuit amplifies a pulse width of the signal generated by the first circuit means.

Abstract: A semiconductor memory device of the present invention comprises an internal power supplying circuit electrically connected to an external power supply having an external source potential and for supplying an internal potential lower than the external source potential, a precharging circuit for supplying a half potential of the internal potential to each of memory cells and bit lines, and a switching circuit electrically connected between each bit line and the precharging circuit and controlled based on an equalize signal output from a control circuit and having the same potential as the external source potential. The semiconductor memory device of such a type that even if a potential on each bit line increases excessively, such a potential does not exert an influence on each memory cell, can be realized owing to the above structure.