Pixel driving circuit

A pixel circuit includes a light emitting diode, a capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor and a sixth transistor. The first transistor is configured to provide a driving current to the light emitting diode. The light emitting diode, the second transistor, the first transistor and the third transistor are series coupled and electrically coupled between first system voltage terminal and second system voltage terminal. The capacitor electrically couple to the gate terminal of the first transistor. The fourth transistor and the fifth transistor are series coupled and electrically coupled to first terminal of the first transistor. The sixth transistor is coupled to the second terminal of the first transistor. The capacitor is configured to provide an adjustable voltage to the gate terminal of the first transistor to adjust the driving current provided to the light emitting diode.