Semiconductor integrated circuit device in which influence of power supply noise on internal circuitry during operation of input/output buffer is prevented

摘要

In a system chip, power supply lines and ground lines are provided independently for input/output buffer circuit, a logic circuit, memory cell array and so on. The word line is held at a negative potential when not selected. At an initial stage of sense amplifier operation, sense amplifier operates with external power supply potential Vcc directly supplied thereto, and after a prescribed time period, it operates receiving internal power supply potential Vcc as output from an internal voltage converting circuit.