A pixel circuit has a light emitting diode, a first driving transistor, a second driving transistor, a capacitor, and a switch unit. When a scan signal is asserted, the switch unit couples sources/drains of the second driving transistor respectively to a first and a second source/drain of the first driving transistor, and couples a gate and second source/drain of the first driving transistor together. When the scan signal is de-asserted, the switch unit decouples one of the sources/drains of the second driving transistor from the first/second source/drain of the first driving transistor, and decouples the gate from the second source/drain of the first driving transistor.