Output buffer with improved output deviation and source driver for flat panel display having the output buffer

A source driver of a flat panel display that generates a gray data signal and outputs the gray data signal to a display panel formed of an array of a plurality of display cells, the source driver comprising;

• a storage unit that stores a digital data signal provided by an external device;
• a digital-to-analog (D/A) conversion unit that receives the digital data signal from the storage unit and converts the digital data signal into an analog gray data signal, and
• an output buffer unit that provides the analog gray data signal to the display panel,
• wherein the output buffer unit includes a plurality of output buffers, and each of the output buffers includes a plurality of transistors having different driving capabilities.

A flat panel display comprising:

• a display panel that includes a plurality of gate lines, a plurality of source lines, and an array of a plurality of display cells that are respectively connected to the plurality of gate lines and the plurality of source lines;
• a gate driver that generates a plurality of gate driving signals and respectively applies the plurality of gate driving signals to the plurality of gate lines of the display panel;
• a source driver that generates an analog gray voltage signal based on a digital input data signal, the analog gray voltage signal being used to drive the array of display cells of the display panel;
• and
• a controller that controls the gate driver and the source driver and applies the digital input data signal to the source driver,
• wherein the source driver includes:
• a digital-to-analog (D/A) conversion unit that converts the digital input data signal into the analog gray voltage signal, and
• an output buffer unit that provides the analog gray data signal to the display panel via the plurality of source lines, wherein the output buffer unit includes a plurality of output buffers, and each of the plurality output buffers includes a plurality of transistors having different driving capabilities.