Abstract: A level shifter and a data output buffer adapted for use in a semiconductor memory device including a memory cell for storing data, a sense amplifier for amplifying data read from the memory cell and generating an ECL-level output signal, and a level shifter for converting the ECL-level output signals into a CMOS-level signal, wherein the level shifter has a level shifting means receiving the ECL-level data signals, converting the input data to CMOS-levels, and outputting a result, and a delay for delaying the result so as to control its current consumption of the level shifter.

Abstract: A data output circuit of a semiconductor memory device matches an equalizing level of voltages at data lines in a pair with a logic threshold voltage of data output buffers. The data output circuit having an equalizing transistor connected between first and second nodes connected to the outputs of a sense amplifier, includes a threshold voltage control circuit disposed between the sense amplifier and the data output buffers for allowing a threshold voltage of the data output buffers to match with the equalizing level of the voltages at the first and second nodes. The threshold voltage control circuit has the same structure and characteristics as that of the output buffers, so as to ensure that the logic threshold voltage of the data output buffers matches with the equalizing level of the voltages at the first and second nodes.