A half-power buffer amplifier includes an amplification unit including first and second nodes, the amplification unit configured to differentially amplify a differential input signal and to output a differentially amplified output signal, a first output unit including a first buffer unit between a first power source having a first voltage and a second power source having a second voltage, a second buffer unit between the first and second power sources, and a first switch unit between the first and second buffer units, and a second output unit including a third buffer unit between the second power source and a third power source having a third voltage, a fourth buffer unit between the second and third power sources, and a second switch unit between the third and fourth buffer units. Each of the first to third buffer units receives the differentially amplified output signal. The first switch unit is turned on or off based on or in response to a pre-driving control signal.