A sense amplifier includes a pair of sense bit lines and first and second MOS sense amplifiers. The first MOS sense amplifier has a first pair of MOS transistors of first conductivity type therein, which are electrically coupled across the pair of sense bit lines. This electrically coupling is provided so that each of the first pair of MOS transistors has a first source/drain terminal electrically connected to a corresponding one of the pair of sense bit lines and the second source/drain terminals of the first pair of MOS transistors are electrically connected together. The first pair of MOS transistors of first conductivity type is configured to have different threshold voltages or support different threshold voltage biasing. The second MOS sense amplifier has a first pair of MOS transistors of second conductivity type therein, which are electrically coupled across the pair of sense bit lines.