Abstract: There is disclosed a sense amplifier for a semiconductor memory device comprising a cross coupled latch for sense-amplifying data signals on bit lines, a pull-up driver connected between the cross coupled latch and a supply voltage source for controlling an amount of current of a supply voltage being supplied to the cross coupled latch, a pull-down driver connected between the cross coupled latch and a ground voltage source for controlling an amount of current of a ground voltage being supplied no the cross coupled latch, and a voltage detector for detecting a difference between the supply voltage and the ground voltage and controlling the pull-up driver and the pull-down driver in accordance with the detected result. According to the present invention, when the voltage difference is high in level, the sense amplifier minimizes a noise component being generated. In the case where the voltage difference is low in level, the sense amplifier amplifies the data signals on the bit lines at a high speed.