A electro-luminescent (EL) display panel includes a substrate, a pixel and a Digital-Analogy Converter (DAC). The substrate includes a first area and a second area. A Thin Film Transistor (TFT) formed in the first area has a first channel doping concentration, and a TFT formed in the second area has a second channel doping concentration. The pixel is disposed in the second area. The DAC includes switch circuits and current sources. Each switch circuit disposed in the second area is selectively turned on according to corresponding grey levels. Each current source disposed in the first area is electrically connected to the corresponding switch circuit and selectively supplying current to generate a pixel current according to conducting states of the corresponding switch circuit. A threshold voltage variation of the TFT formed in the first area is less than that of the TFT formed in the second area.