SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE

摘要

PURPOSE:To obtain an accurately set boost voltage without influenced by process variance of a threshold voltage of an MOSFET by using and switch controlling a depression type MOSFET. CONSTITUTION:A common source line CS of an FAMOS transistor is grounded through a depression type MOSFET Q10 receiving a writing signal we. To the gates of depression type MOSFET Q11 and Q12, an internal writing control signal we of 5V system outputted from a control circuit CONT is supplied. In the case of a reading operation, the internal writing control signal we is brought to a high level of about 5V. In this case, all the MOSFET Q11 and Q12 are turned on to a 5V system selecting signal outputted from an X address decoder XDCR and an output of the X address decoder XDCR is transmitted to the respective word lines as it is. In the case of a writing operation, the internal writing control signal we is brought to a low level of about 0V.