Patent attributes
In a power-up signal generating device, a power-up signal is activated at a certain level of the power supply voltage VDD by adjusting the turn-on resistance value of the MOS transistor so that the chip reliability can be improved. The power-up signal generating device comprises a reference voltage generating unit, a bias level adjusting unit, a bias signal generating unit and a signal outputting unit. The reference voltage generating unit generates a reference voltage. The bias level adjusting unit receives the reference voltage as an input for controlling a voltage level of a bias signal in a constant level. The bias signal generating unit generates the bias signal under control of the bias level adjusting unit. The signal outputting unit outputs a power-up signal depending on the voltage level of the bias signal.