A read reference current generator includes a temperature coefficient (TC) controller configured to adjust a temperature coefficient in response to a first control signal and generate a read reference current having an adjusted temperature coefficient, a plurality of replica circuits configured to receive the read reference current and adjust an absolute value of the read reference current with different scale factors to generate a plurality of branch currents, and a plurality of switches configured to control connection of the TC controller and the plurality of replica circuits in response to a second control signal, wherein an equivalent resistance value of each of the plurality of replica circuits corresponds to a multiple of an equivalent resistance value of a data read path, and the data read path includes a selected memory cell and a clamping circuit clamping a voltage level of a selected bit line to a determined value.