Source drivers and display devices that include such source drivers are provided that may be used to control the amount of output current from an output buffer. These source drivers may comprise a buffer that is configured to receive an input signal and a control circuit that is coupled to the buffer that is configured to control an output current level of the buffer. The control circuit may comprise a bias voltage generator that is configured to generate a plurality of bias voltages, and the output current level of the buffer may be controlled based on the plurality of bias voltages. Methods of controlling the amount of current output from an output buffer of the source driver and methods of driving a display device are also provided.