Abstract: A boosting voltage level detector for a semiconductor memory device which utilizes a boosting voltage the level of which is higher than that of a power supply voltage, which includes a pull-up portion and a pull-down portion. In a preferred embodiment, the pull-up portion includes a PMOS transistor and a first NMOS transistor connected in series between the power supply voltage and an output node, and the pull-down portion includes second and third NMOS transistors connected in series between the output node and ground. The PMOS transistor has a gate electrode which is coupled to ground, and thus functions as a current source. The second NMOS transistor has a gate electrode which is coupled to a reference voltage, and thus functions as a resistor. The gate electrodes of the first and third NMOS transistors are commonly coupled to the boosting voltage. The detector further includes an inverter circuit coupled to the output node.

Abstract: A voltage boosting circuit for a semiconductor memory device has a clock generator for supplying a chip master clock determining an active state and a stand-by state in respective response to first and second states thereof, for generating a detector control signal a first delay time after the first state of the chip master clock is generated, and for generating a latch control signal a second delay time after the first state of the chip master clock is generated. A boosting voltage detector responds to the detector control signal and the latch control signal to generate a detecting signal indicative of a current state of a boosting voltage potential. First and second boosting voltage generators generate the boosting voltage potential, respectively operating in the stand-by state and active state in accordance with the detecting signal and delayed chip master clock signal.

Abstract: A semiconductor memory device has a plurality of memory cell arrays, each with a normal cell array and a spare cell array. Fuse circuits are programmable to substitute a spare-cell-array word line for a defective word line in any normal cell array. When a defective word line is addressed, a fuse circuit activates a spare-cell-array word line, and also activates a redundancy signal line. A single redundancy signal line is shared by all fuse circuits and block select circuits. Block select circuits normally enable the cell array that includes the defective word line, however, the block select circuits are disabled when the defective word line has been replaced by a spare word line an another block.

Abstract: An internal supply voltage generation circuit, producing an internal supply voltage during a normal mode of operation and an external supply voltage during a burn-in mode of operation. The circuit including a plurality of fuses, the operation of which establishes the burn-in mode of operation, and controls a variable burn-in voltage level.

Abstract: A charge pump circuit of a substrate voltage generator used for a semiconductor memory device, comprising a first transistor whose channel is connected between a first pumping capacitor and a substrate node and a second transistor whose channel is connected between a second pumping capacitor and the substrate node, whereby a negative voltage generated by the first pumping capacitor in response to the substrate voltage and clock signals turns on the second transistor which performs charge pumping from the substrate node. Thus the substrate voltage is made to have sufficient coupling-down so as to stabilize the substrate voltage even with a low source voltage.