A display unit is provided. The display unit includes a light-emitting diode, a driving transistor, and a power supply system. The light-emitting diode comprises a cathode and an anode. The driving transistor comprises a source, a drain, and a gate, wherein the gate receives a first voltage, the drain is coupled to a second voltage via the light-emitting diode and the gate receives a third voltage. The power supply system is coupled to the drain of the driving transistor, providing the second voltage in response to the voltage of the drain of the driving transistor.